Spracherkennung für: .g vermutete Sprache: Unknown {[0] [0] [0]} [Methode: Schwerpunktbildung, einfache Gewichte, sechs Dimensionen]
#############################################################################
##
#W ctadmin.g GAP character table library Thomas Breuer
#W Ute Schiffer
##
## This file contains the data of the {\GAP} character table library that is
## not automatically produced from the library files.
##
#############################################################################
##
TBLNAME:= Concatenation( List( PKGNAME,
x -> Concatenation( x, "ctbllib/data/;" ) ) );
#############################################################################
##
#F Immutable( <obj> )
#F MakeImmutable( <obj> )
#F MakeReadOnlyGlobal( <obj> )
#F TestPackageAvailability( ... )
#F IsPosInt( <n> )
#V TOM_TBL_INFO
#F ListWithIdenticalEntries( <len>, <entry> )
#F BindGlobal
#F ValueGlobal
##
## These are used in `ctprimar.tbl' but not available in {\GAP}~3.4.
##
if not IsBound( IsEmpty ) then
IsEmpty:= list -> ( list = [] );
fi;
if not IsBound( Immutable ) then
Immutable:= x -> x;
fi;
if not IsBound( MakeImmutable ) then
MakeImmutable:= Ignore;
fi;
if not IsBound( MakeReadOnlyGlobal ) then
MakeReadOnlyGlobal:= Ignore;
fi;
if not IsBound( TestPackageAvailability ) then
TestPackageAvailability:= function( arg ) return true; end;
fi;
if not IsBound( IsPackageMarkedForLoading ) then
IsPackageMarkedForLoading:= function( arg ) return true; end;
fi;
if not IsBound( IsPosInt ) then
IsPosInt:= ( n -> IsInt( n ) and 0 < n );
fi;
if not IsBound( TOM_TBL_INFO ) then
TOM_TBL_INFO:= [];
fi;
if not IsBound( ListWithIdenticalEntries ) then
ListWithIdenticalEntries:= function( len, entry )
return List( [ 1 .. len ], i -> entry );
end;
fi;
if not IsBound( DuplicateFreeList ) then
DuplicateFreeList:= function( list )
local l, i;
l:= [];
for i in list do
if not i in l then
Add( l, i );
fi;
od;
return l;
end;
fi;
if not IsBound( BindGlobal ) then
BindGlobal:= function( varname, value )
if varname = "LIBLIST" then
LIBLIST:= value;
elif varname = "TOM_TBL_INFO" then
TOM_TBL_INFO:= value;
else
Error( "BindGlobal is not fully available in GAP 3" );
fi;
end;
fi;
ConstructIndexTwoSubdirectProduct:= 0;
ConstructSubdirect:= 0;
ConstructPermuted:= 0;
ConstructAdjusted:= 0;
ConstructFactor:= 0;
ConstructWreathSymmetric:= 0;
if not IsBound( ValueGlobal ) then
ValueGlobal:= function( varname )
local constr, pos;
constr:= [ "ConstructMGA", ConstructMixed,
"ConstructMixed", ConstructMixed,
"ConstructProj", ConstructProj,
"ConstructDirectProduct", ConstructDirectProduct,
"ConstructSubdirect", ConstructSubdirect,
"ConstructIndexTwoSubdirectProduct",
ConstructIndexTwoSubdirectProduct,
"ConstructWreathSymmetric", ConstructWreathSymmetric,
"ConstructIsoclinic", ConstructIsoclinic,
"ConstructV4G", ConstructV4G,
"ConstructGS3", ConstructGS3,
"ConstructPermuted", ConstructPermuted,
"ConstructAdjusted", ConstructAdjusted,
"ConstructFactor", ConstructFactor,
"ConstructClifford", ConstructClifford ];
pos:= Position( constr, varname );
if pos <> false then
return constr[ pos+1 ];
else
Error( "ValueGlobal is not fully available in GAP 3" );
fi;
end;
fi;
#############################################################################
##
#V CharTableDoubleCoverAlternating
#V CharTableDoubleCoverSymmetric
##
## These are used in `data/ctgeneri.tbl' but are not available in {\GAP}~3.
##
CharTableDoubleCoverAlternating := rec();
CharTableDoubleCoverSymmetric := rec();
#############################################################################
##
#F Conductor( <obj> )
##
## This is used in `data/ctgeneri.tbl'.
##
Conductor:= NofCyc;
#############################################################################
##
#V GAP_4_SPECIALS
##
## list of pairs whose first entries are the `identifier' values
## of tables whose `construction' component would require {\GAP}~4 features,
## and the second entries are the corresponding functions that do the same
## in {\GAP}~3.
##
GAP_4_SPECIALS := [
[ "2.(2xF4(2)).2", function( tbl )
local pi, irr, i, outer1, outer2, chi, j, adjustch, adjustcl, z;
pi:= (2,3)(6,7)(10,11)(14,15)(18,19)(22,23)(28,29)(32,33)(40,41)(44,45)
(48,49)(58,59)(62,63)(66,67)(70,71)(74,75)(78,79)(82,83)(86,87)(90,91)
(96,97)(100,101)(110,111)(114,115)(118,119)(122,123)(126,127)(132,133)
(136,137)(140,141)(144,145)(150,151)(158,159)(162,163)(166,167)(170,
171)(174,175)(182,183)(186,187)(190,191)(196,197)(200,201)(204,205)
(208,209)(212,213)(228,229)(234,235)(246,247)(254,255)(258,259)(264,
265)(268,269)(272,273)(276,277)(280,281)(284,285)(288,289)(292,293)
(296,297)(300,301);
ConstructDirectProduct( tbl, [["2.F4(2).2"],["Cyclic",2]], pi, () );
Unbind( tbl.orders );
Unbind( tbl.fusions[ Length( tbl.fusions ) ] );
Unbind( tbl.fusions[ Length( tbl.fusions ) ] );
irr:= tbl.irreducibles;
for i in [ 1 .. Length( irr ) ] do
irr[i]:= ShallowCopy( irr[i] );
od;
outer1:= [215..302];
outer2:= [3,4,7,8,11,12,15,16,19,20,23,24,26,29,30,33,34,36,38,41,42,45,46,
49,50,52,54,56,59,60,63,64,67,68,71,72,75,76,79,80,83,84,87,88,91,92,94,97,
98,101,102,104,106,108,111,112,115,116,119,120,123,124,127,128,130,133,134,
137,138,141,142,145,146,148,151,152,154,156,159,160,163,164,167,168,171,172,
175,176,178,180,183,184,187,188,191,192,194,197,198,201,202,205,206,209,210,
213,214,216,218,220,222,224,226,229,230,232,235,236,238,240,242,244,247,248,
250,252,255,256,259,260,262,265,266,269,270,273,274,277,278,281,282,285,286,
289,290,293,294,297,298,301,302];
i:= E(4);
for chi in irr do
if chi[1] = chi[2] then
if chi[1] <> chi[2] or chi[1] <> chi[3] then
for j in outer1 do
chi[j]:= i * chi[j];
od;
fi;
else
for j in outer2 do
chi[j]:= i * chi[j];
od;
fi;
od;
adjustch:= [183,184,185,186,191,192,193,194,195,196,197,198,199,200,201,202,
209,210,211,212,217,218,219,220,223,224,225,226,237,238,239,240,265,266,267,
268,271,272,273,274,275,276,277,278,287,288,289,290,291,292,293,294,295,296,
297,298,299,300,301,302];
adjustcl:=[227,228,229,230,233,234,235,236,245,246,247,248,253,254,255,256,
257,258,259,260,263,264,265,266,267,268,269,270,271,272,273,274,275,276,277,
278,279,280,281,282,283,284,285,286,287,288,289,290,291,292,293,294,295,296,
297,298,299,300,301,302];
z:= E(8);
for chi in irr{ adjustch{ [ 1, 3 .. 59 ] } } do
for j in adjustcl do
chi[j]:= z * chi[j];
od;
od;
z:= E(8)^3;
for chi in irr{ adjustch{ [ 2, 4 .. 60 ] } } do
for j in adjustcl do
chi[j]:= z * chi[j];
od;
od;
end ],
[ "C9Y3.3^5.U4(2)", function( tbl )
local e, e8, e2, e7, chi, i;
ConstructDirectProduct( tbl, [["Cyclic",3],["3.3^5.U4(2)"]] );
Unbind( tbl.orders );
Unbind( tbl.fusions[ Length( tbl.fusions ) ] );
Unbind( tbl.fusions[ Length( tbl.fusions ) ] );
for i in [ 1 .. Length( tbl.irreducibles ) ] do
tbl.irreducibles[i]:= ShallowCopy( tbl.irreducibles[i] );
od;
e:= E(9);
e8:= E(9)^8;
e2:= E(9)^2;
e7:= E(9)^7;
for chi in tbl.irreducibles do
if chi[2] = chi[1] * E(3) then
for i in [ 86 .. 170 ] do
chi[i]:= chi[i] * e8;
od;
for i in [ 171 .. 255 ] do
chi[i]:= chi[i] * e7;
od;
elif chi[2] = chi[1] * E(3)^2 then
for i in [ 86 .. 170 ] do
chi[i]:= chi[i] * e;
od;
for i in [ 171 .. 255 ] do
chi[i]:= chi[i] * e2;
od;
fi;
od;
end ],
[ "Isoclinic(3.U3(8)x3)", function( tbl )
local dp, aux;
dp:= CharTableDirectProduct( CharTable( "3.U3(8)" ),
CharTable( "Cyclic", 9 ) );
aux:= CharTableFactorGroup( dp, [ 1, 16, 22 ] );
tbl.centralizers:= aux.centralizers;
tbl.powermap:= aux.powermap;
tbl.irreducibles:= aux.irreducibles;
end ],
[ "Isoclinic(U3(8).3_3x3)", function( tbl )
local dp, aux;
dp:= CharTableDirectProduct( CharTable( "U3(8).3_3" ),
CharTable( "Cyclic", 9 ) );
aux:= CharTableNormalSubgroup( dp, Concatenation( [ 1, 4 .. 124 ],
[128,131,134,138,141,144,146,149,152,156,159,162,164,167,170,174,
177,180,182,185,188,192,195,198,200,203,206,210,213,216,218,221,
224,228,231,234,236,239,242,246,249,252] ) );
tbl.centralizers:= aux.centralizers;
tbl.powermap:= aux.powermap;
tbl.irreducibles:= aux.irreducibles;
end ],
];
#############################################################################
##
#F IrreducibleCharactersOfIsoclinicGroup( <irr>, <center>, <outer>, <xpos> )
##
IrreducibleCharactersOfIsoclinicGroup:= function( irr, center, outer, xpos )
local nonfaith, faith, irreds, root1, chi, values, root2;
# Adjust faithful characters in outer classes.
nonfaith:= [];
faith:= [];
irreds:= [];
root1:= E(4);
if Length( center ) = 1 then
# The central subgroup has order two.
for chi in irr do
values:= chi;
if values[ center[1] ] = values[1] then
Add( nonfaith, values );
else
values:= ShallowCopy( values );
values{ outer }:= root1 * values{ outer };
Add( faith, values );
fi;
Add( irreds, values );
od;
else
# The central subgroup has order four.
root2:= E(8);
for chi in irr do
values:= chi;
if ForAll( center, i -> values[i] = values[1] ) then
Add( nonfaith, values );
else
values:= ShallowCopy( values );
if ForAny( center, i -> values[i] = values[1] ) then
values{ outer }:= root1 * values{ outer };
elif values[ xpos ] / values[1] = root1 then
values{ outer }:= root2 * values{ outer };
else
# If B is the matrix for g in G, the matrix for gz in H
# depends on the character value of z^2 = x;
# we have to choose the same square root for the whole character,
# so the two possibilities differ just by the ordering of the two
# extensions which we get.
values{ outer }:= root2^-1 * values{ outer };
fi;
Add( faith, values );
fi;
Add( irreds, values );
od;
fi;
return rec( all:= irreds, nonfaith:= nonfaith, faith:= faith );
end;
#############################################################################
##
#F CharTableIsoclinic( <tbl> )
#F CharTableIsoclinic( <tbl>, <classes_of_normal_subgroup> )
#F CharTableIsoclinic( <tbl>, <nsg>, <center> )
##
## for table of groups $2.G.2$, the character table of the isoclinic group
## (see ATLAS, Chapter 6, Section 7)
##
CharTableIsoclinic;
CharTableIsoclinic := function( arg )
local i, # 'E(4)'
j, # loop variable
chi, # one character
orders,
class,
map,
tbl, # input table
linear, # linear characters of 'tbl'
isoclinic, # the isoclinic table, result
center, # nontrivial class(es) contained in the center
nsg, # index 2 subgroup
outer, # classes outside the index 2 subgroup
images,
factorfusion,
reg, # restriction to regular classes
half, kernel, xpos, irreds, invfusion, k, ypos, old;
# check the argument
if not ( Length( arg ) in [ 1 .. 3 ] and IsCharTable( arg[1] ) )
or ( Length( arg ) = 2 and not IsList( arg[2] ) ) then
Error( "usage: CharTableIsoclinic( tbl[, classes_of_nsg] )");
fi;
# get the ordinary table if necessary
if IsBound( arg[1].ordinary ) then
tbl:= arg[1].ordinary;
else
tbl:= arg[1];
fi;
if not IsBound( tbl.powermap ) then
tbl.powermap:= [];
fi;
# compute the isoclinic table of the ordinary table
# Get the classes of the normal subgroup of index 2.
if Length( arg ) = 1 then
nsg:= false;
center:= false;
elif Length( arg ) = 2 then
# The 2nd argument describes the normal subgroup of index 2
# or the centre.
if IsList( arg[2] ) and Sum( tbl.classes{ arg[2] } ) = tbl.size / 2 then
nsg:= arg[2];
center:= false;
else
nsg:= false;
center:= arg[2];
fi;
else
nsg:= arg[2];
center:= arg[3];
if IsInt( center ) then
center:= [ center ];
fi;
fi;
# Check `nsg'.
if nsg = false then
# Identify the unique normal subgroup of index 2.
half:= tbl.size / 2;
linear:= Filtered( tbl.irreducibles, x -> x[1] = 1 );
kernel:= Filtered( List( linear, KernelChar ),
ker -> Sum( tbl.classes{ ker } ) = half );
elif IsList( nsg ) and Sum( tbl.classes{ nsg } ) = tbl.size / 2 then
kernel:= [ nsg ];
else
Error( "normal subgroup described by <nsg> must have index 2" );
fi;
# Check `center'.
if center = false then
# Get the unique central subgroup of order 2 in the normal subgroup.
center:= Filtered( [ 1 .. Length( tbl.classes ) ],
i -> tbl.classes[i] = 1 and tbl.orders[i] = 2
and ForAny( kernel, n -> i in n ) );
if Length( center ) <> 1 then
Error( "central subgroup of order 2 not uniquely determined,\n",
"use CharacterTableIsoclinic( <tbl>, <classes>, <center> )" );
fi;
elif IsPosInt( center ) then
center:= [ center ];
else
center:= Difference( center, [ 1 ] );
fi;
# If there is more than one index 2 subgroup
# and if there is a unique central subgroup $Z$ of order 2 or 4
# then consider only those index 2 subgroups containing $Z$.
if 1 < Length( kernel ) then
kernel:= Filtered( kernel, ker -> IsSubset( ker, center ) );
fi;
if Length( kernel ) <> 1 then
Error( "normal subgroup of index 2 not uniquely determined,\n",
"use CharacterTableIsoclinic( <tbl>, <classes_of_nsg> )" );
fi;
nsg:= kernel[1];
if not IsSubset( nsg, center ) then
Error( "<center> must lie in <nsg>" );
elif ForAny( center, i -> tbl.classes[i] <> 1 ) then
Error( "<center> must be a list of positions of central classes" );
elif Length( center ) = 1 then
xpos:= center[1];
if tbl.orders[ xpos ] <> 2 then
Error( "<center> must list the classes of a central subgroup" );
fi;
elif Length( center ) = 3 and ForAny( center, i -> tbl.orders[i] = 4 ) then
xpos:= First( center, i -> tbl.orders[i] = 4 );
else
Error( "the central subgroup must have order 2 or 4" );
fi;
# classes outside the normal subgroup
outer:= Difference( [ 1 .. Length( tbl.classes ) ], nsg );
# Adjust faithful characters in outer classes.
irreds:= IrreducibleCharactersOfIsoclinicGroup( tbl.irreducibles, center,
outer, xpos );
# make the record of the isoclinic table
isoclinic:= rec(
identifier := Concatenation( "Isoclinic(",
tbl.identifier, ")" ),
size := tbl.size,
centralizers := Copy( tbl.centralizers ),
classes := Copy( tbl.classes ),
orders := Copy( tbl.orders ),
fusions := [],
fusionsource := [],
powermap := Copy( tbl.powermap ),
irreducibles := irreds.all,
operations := CharTableOps );
isoclinic.order:= isoclinic.size;
isoclinic.name:= isoclinic.identifier;
# get the fusion map onto the factor group modulo the center
factorfusion:= CollapsedMat( irreds.nonfaith, [] ).fusion;
invfusion:= InverseMap( factorfusion );
# adjust the power maps
for j in [ 1 .. Length( isoclinic.powermap ) ] do
if IsBound( isoclinic.powermap[j] ) then
map:= isoclinic.powermap[j];
# For $p \bmod |z| = 1$, the map remains unchanged,
# since $g^p = h$ implies $(gz)^p = hz^p = hz$ then.
# So we have to deal with the cases $p = 2$ and $p$ congruent
# to the other odd positive integers up to $|z| - 1$.
k:= j mod ( 2 * Length( center ) + 2 );
if j = 2 then
ypos:= xpos;
elif k <> 1 then
ypos:= Powmap( tbl.powermap, (k-1)/2, xpos );
fi;
if k <> 1 then
for class in outer do
old:= map[ class ];
images:= invfusion[ factorfusion[ old ] ];
if IsList( images ) then
if Length( center ) = 1 then
# The image is ``the other'' class.
images:= Difference( images, [ old ] );
else
# It can happen that the class powers to itself.
# Use the character values for the decision.
images:= Filtered( images,
x -> ForAll( irreds.faith,
chi -> chi[ old ] = 0 or
chi[x] / chi[ old ] = chi[ ypos ] / chi[1] ) );
fi;
map[ class ]:= images[1];
if j = 2 then
isoclinic.orders[ class ]:= 2 * tbl.orders[ images[1] ];
fi;
fi;
od;
fi;
fi;
od;
# if we want the isoclinic table of a Brauer table then
# transfer the normal subgroup information to the regular classes,
# and adjust the irreducibles
if tbl <> arg[1] then
reg:= CharTableRegular( isoclinic, arg[1].prime );
factorfusion:= GetFusionMap( reg, isoclinic );
reg.irreducibles:= Copy( arg[1].irreducibles );
center:= Position( factorfusion, center );
outer:= Filtered( [ 1 .. Length( reg.centralizers ) ],
x -> factorfusion[x] in outer );
for chi in Filtered( reg.irreducibles,
x -> x[ center ] <> x[1] ) do
for class in outer do
chi[ class ]:= i * chi[ class ];
od;
od;
isoclinic:= reg;
fi;
# adjust the table name
isoclinic.identifier:= Concatenation( "Isoclinic(",
arg[1].identifier, ")" );
# return the result
return isoclinic;
end;
#############################################################################
##
#V LIBTABLE
##
LIBTABLE:= rec(
TABLEFILENAME := "",
LOADSTATUS := rec(),
clmelab := [],
clmexsp := [] );
#############################################################################
##
#F GALOIS( <chars>, <list> )
#F TENSOR( <chars>, <list> )
##
## are global variables used to store the library tables in compressed form.
##
## The entry '[GALOIS,[<i>,<j>]]' in the 'irreducibles' or 'projectives'
## component of a library table means the <j>-th Galois conjugate of
## the <i>-th character.
##
## The entry '[TENSOR,[<i>,<j>]]' in the 'irreducibles' or 'projectives'
## component of a library table means the tensor product of the <i>-th
## and the <j>-th character.
##
#F EvalChars( <chars> )
##
## replaces all entries of the form '[<func>,<list>]' in the list <chars>
## by the result '<func>( <chars>, <list> )'.
##
GALOIS := function( chars, li )
return List( chars[ li[1] ], x -> GaloisCyc( x, li[2] ) );
end;
TENSOR := function( chars, list )
local i, chi, psi, result;
chi:= chars[ list[1] ];
psi:= chars[ list[2] ];
result:= [];
for i in [ 1 .. Length( chi ) ] do result[i]:= chi[i] * psi[i]; od;
return result;
end;
EvalChars := function( chars )
local i;
for i in [ 1 .. Length( chars ) ] do
if IsFunc( chars[i][1] ) then
chars[i]:= chars[i][1]( chars, chars[i][2] );
fi;
od;
end;
#############################################################################
##
#F MBT( <arg> )
##
## The library format of Brauer tables is a call to the function
## 'MBT', with the following arguments.
##
## 1. identifier of the table
## 2. field characteristic
## 3. text (list of lines)
## 4. block
## 5. defect
## 6. basic set
## 7. Brauer tree information
## 8. inverses of decomposition matrices restricted to basic sets
## 9. blocks of proper factor groups
## 10. list of generators for the group of table automorphisms
## 11. 2nd indicator (in characteristic 2 only)
## 12. (optional) record with additional components
##
MBT := function( arg )
local i, record;
record:= rec(
text := arg[ 3],
prime := arg[ 2],
block := arg[ 4],
defect := arg[ 5],
basicset := arg[ 6],
brauertree := arg[ 7],
decinv := arg[ 8],
factorblocks := arg[ 9],
automorphisms := arg[10],
indicator := arg[11]
);
for i in RecFields( record ) do
if record.(i) = 0 then
Unbind( record.(i) );
fi;
od;
if Length( arg ) = 12 then
for i in RecFields( arg[12] ) do
record.(i):= arg[12].(i);
od;
fi;
LIBTABLE.( LIBTABLE.TABLEFILENAME ).(
Concatenation( arg[1], "mod", String( arg[2] ) ) ):= record;
end;
#############################################################################
##
#F MOT( <arg> )
##
## The library format of ordinary character tables is a call to the function
## 'MOT', with the following arguments.
##
## 1. identifier of the table
## 2. text (list of lines)
## 3. list of centralizer orders
## 4. list of power maps
## 5. list of irreducibles
## 6. list of generators for the group of table automorphisms
## 7. (optional) construction of the table
##
## Each fusion is added by 'ALF', any other component of the table must be
## added individually via 'ARC( <identifier>, <compname>, <compval> )'.
##
## 'MOT' constructs a (preliminary) table record, and puts it into the
## component 'LIBTABLE.TABLEFILENAME' of 'LIBTABLE'.
## The 'fusionsource' and 'projections' are dealt with when the table is
## constructed by 'CharTableLibrary'.
## Admissible names are notified by 'ALN( <name>, <othernames> )'.
##
MOT := function( arg )
local record, i;
# Construct the table record.
record:= rec(
text := arg[2],
centralizers := arg[3],
powermap := arg[4],
fusions := [],
irreducibles := arg[5],
automorphisms := arg[6]
);
for i in RecFields( record ) do
if record.(i) = 0 then
Unbind( record.(i) );
fi;
od;
if IsBound( arg[7] ) then
record.construction:= arg[7];
fi;
# Store the table record.
LIBTABLE.( LIBTABLE.TABLEFILENAME ).( arg[1] ):= record;
#Print( "stored for ", arg[1], " in ", LIBTABLE.TABLEFILENAME, "\n" );
end;
#############################################################################
##
#F LowercaseString( <string> ) . . . string consisting of lower case letters
##
LowercaseString := function( str )
local alp, ALP, result, i, pos;
alp:= "abcdefghijklmnopqrstuvwxyz";
ALP:= "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
result:= "";
for i in str do
pos:= Position( ALP, i );
if pos = false then
Add( result, i );
else
Add( result, alp[ pos ] );
fi;
od;
return result;
end;
#############################################################################
##
#F NotifyCharTableName( <firstname>, <newnames> )
##
## notifies the new names in the list <newnames> for the library table with
## first name <firstname>, if there is no other table yet for that some of
## these names are admissible.
##
NotifyCharTableName := function( firstname, newnames )
local lower,
pos,
pos2,
name,
j;
if not ( IsString( firstname )
and IsList( newnames ) and ForAll( newnames, IsString ) ) then
Error( "<firstname> and entries in list <newnames> must be strings" );
fi;
if ForAny( [ 1 .. Length( firstname ) - 2 ],
x -> firstname{ [ x .. x+2 ] } = "mod" ) then
Error( "Brauer tables must not have explicitly given 'othernames'" );
fi;
pos:= Position( LIBLIST.firstnames, firstname );
if pos = false then
Error( "no GAP library table with first name '", firstname, "'" );
fi;
lower:= List( newnames, LowercaseString );
if ForAny( lower, x -> x in LIBLIST.allnames ) then
Error( "<newnames> must contain only new names" );
fi;
Append( LIBLIST.allnames, lower );
Append( LIBLIST.position, List( lower, x -> pos ) );
SortParallel( LIBLIST.allnames, LIBLIST.position );
end;
#############################################################################
##
#F NotifyCharTable( <firstname>, <filename>, <othernames> )
##
## notifies a new ordinary table to the library.
## This table has 'identifier' component <firstname>,
## it is contained in the file with name <filename>, and
## it is known to have also the names contained in the list <othernames>.
##
## 'NotifyCharTable' modifies the global variable 'LIBLIST' after having
## checked that there is no other table yet with admissible name equal to
## <firstname> or contained in <othernames>.
##
NotifyCharTable := function( firstname, filename, othernames )
local len, pos;
if not ( IsString( firstname ) and IsString( filename )
and IsList( othernames ) ) then
Error( "<firstname>, <filename> must be strings, ",
"<othernames> must be a list" );
fi;
if LowercaseString( firstname ) in LIBLIST.allnames then
Error( "'", firstname, "' is already a valid name" );
fi;
Add( LIBLIST.firstnames, firstname );
if not filename in LIBLIST.files then
Add( LIBLIST.files, filename );
fi;
len:= Length( LIBLIST.firstnames );
LIBLIST.filenames[ len ]:= Position( LIBLIST.files, filename );
LIBLIST.fusionsource[ len ]:= [];
NotifyCharTableName( firstname, [ firstname ] );
NotifyCharTableName( firstname, othernames );
# Allow natural names.
#T !!
end;
#############################################################################
##
#F LibInfoCharTable( <tblname> )
##
## is a record with components 'firstName' and 'fileName', the former being
## the 'identifier' component of the library table for that <tblname> is an
## admissible name, and the latter being the name of the file in that the
## table is stored;
## if no such table exists in the {\GAP} library then 'false' is returned.
##
## If <tblname> contains the substring "mod" it is regarded as name of a
## Brauer table, the first name is computed from that of the corresponding
## ordinary table (which must exist) also if the library does not contain
## the Brauer table.
##
LibInfoCharTable := function( tblname )
local i, ordinfo, obj, pos;
# Is 'tblname' the name of a Brauer table, i.e., has it the structure
# '<ordname>mod<prime>' ?
# If so, return '<firstordname>mod<prime>' where
# '<firstordname> = LibInfoCharTable( <ordname> ).firstName'.
tblname:= LowercaseString( tblname );
for i in [ 1 .. Length( tblname ) - 2 ] do
if tblname{ [ i .. i+2 ] } = "mod" then
ordinfo:= LibInfoCharTable( tblname{ [ 1 .. i-1 ] } );
if ordinfo <> false then
Append( ordinfo.firstName, tblname{ [ i .. Length( tblname ) ] } );
ordinfo.fileName[3]:= 'b';
fi;
return ordinfo;
fi;
od;
# The name might belong to an ordinary table.
pos:= PositionSorted( LIBLIST.allnames, tblname );
if Length( LIBLIST.allnames ) < pos or
LIBLIST.allnames[ pos ] <> tblname then
pos:= false;
fi;
if pos <> false then
pos:= LIBLIST.position[ pos ];
if pos <> false then
return rec( firstName := Copy( LIBLIST.firstnames[ pos ] ),
fileName := Copy( LIBLIST.files[
LIBLIST.filenames[ pos ] ] ) );
fi;
return false;
fi;
# The name might belong to a generic table.
if tblname in LIBLIST.GENERIC.allnames then
return rec( firstName := LIBLIST.GENERIC.firstnames[
Position( LIBLIST.GENERIC.allnames, tblname ) ],
fileName := "ctgeneri" );
fi;
return false;
end;
#############################################################################
##
#F FirstNameCharTable( <tblname> )
#F FileNameCharTable( <tblname> )
##
FirstNameCharTable := function( name )
name:= LibInfoCharTable( name );
if name <> false then
name:= name.firstName;
fi;
return name;
end;
FileNameCharTable := function( name )
name:= LibInfoCharTable( name );
if name <> false then
name:= name.fileName;
fi;
return name;
end;
#############################################################################
##
#F ALN( <name>, <names> ) . . . . . . . . . . . . . add library table names
##
ALN := NotifyCharTableName;
#############################################################################
##
#F ALF( <from>, <to>, <map> ) . . . . . . . . . . add library table fusions
#F ALF( <from>, <to>, <map>, <text> )
##
ALF := function( arg )
local pos;
if ALN <> Ignore then
# A file is read that does not belong to the official library.
# Check that the names are valid.
pos:= Position( LIBLIST.firstnames, arg[2] );
if not arg[1] in RecFields( LIBTABLE.( LIBTABLE.TABLEFILENAME ) ) then
Error( "source '", arg[1], "' is not stored in 'LIBTABLE.",
LIBTABLE.TABLEFILENAME, "'" );
elif pos = false then
Error( "destination '", arg[2], "' is not a valid first name" );
fi;
# Check whether there was already such a fusion.
if arg[1] in LIBLIST.fusionsource[ pos ] then
Error( "there is already a fusion from '",
arg[1], "' to '", arg[2], "'" );
fi;
# Store the fusion source.
Add( LIBLIST.fusionsource[ pos ], arg[1] );
fi;
if Length( arg ) = 4 then
Add( LIBTABLE.( LIBTABLE.TABLEFILENAME ).( arg[1] ).fusions,
rec( name:= arg[2], map:= arg[3],
text:= Concatenation( arg[4] ) ) );
else
Add( LIBTABLE.( LIBTABLE.TABLEFILENAME ).( arg[1] ).fusions,
rec( name:= arg[2], map:= arg[3] ) );
fi;
end;
#############################################################################
##
#F ACM( <spec>, <dim>, <val> ) . . . . . . . . . . . . . add Clifford matrix
##
## <spec> is one of "elab", "exsp".
## <dim> is the dimension of the Clifford matrix,
## <val> is the Clifford matrix itself.
##
ACM := function( spec, dim, val )
spec:= LIBTABLE.( Concatenation( "clm", spec ) );
if not IsBound( spec[ dim ] ) then
spec[ dim ]:= [];
fi;
Add( spec[ dim ], val );
end;
#############################################################################
##
#F ARC( <name>, <comp>, <val> ) . . . . . . . add component of library table
##
ARC := function( name, comp, val )
local r;
if comp = "CAS" then
for r in val do
if IsBound( r.text ) and not IsString( r.text ) then
r.text:= Concatenation( r.text );
fi;
od;
fi;
LIBTABLE.( LIBTABLE.TABLEFILENAME ).( name ).( comp ):= val;
end;
#############################################################################
##
#F ConstructMixed( <tbl>, <subname>, <factname>, <plan>, <perm> )
##
## <tbl> is the table of a group $m.G.a$,
## <subname> is the name of a subgroup $m.G$ which is a cyclic central
## extension of the (not necessarily simple) group $G$,
## <factname> is the name of the factor group $G.a$ of <tbl> where the
## outer automorphisms $a$ (a group of prime order) acts nontrivially on
## the central $m$.
## Then the faithful characters of <tbl> are induced characters of $m.G$.
##
## <plan> is a list of lists, each containing the numbers of characters of
## $m.G$ that form an orbit under the action of $a$
## (so the induction of characters is simulated).
## <perm> is the permutation that must be applied to the list of characters
## that is obtained on appending the faithful characters to the
## inflated characters of the factor group.
##
## Examples of tables where this is used to compress the library files are
## the tables of $3.F_{3+}.2$ (subgroup $3.F_{3+}$, factor group $F_{3+}.2$)
## and $6.Fi_{22}.2$ (subgroup $6.Fi_{22}$, factor group $2.Fi_{22}.2$).
##
ConstructMixed := function( tbl, sub, fact, plan, perm )
local factfus, # factor fusion from 'tbl' to 'fact'
subfus, # subgroup fusion from 'sub' to 'tbl'
proj, # projection map of 'subfus'
irreds, # list of irreducibles
zero, # list of zeros to be appended to the characters
irr, newirr, entry, sum, chi, i;
fact := CharTable( fact );
sub := CharTable( sub );
factfus := GetFusionMap( tbl, fact );
subfus := GetFusionMap( sub, tbl );
proj := ProjectionMap( subfus );
irreds := List( fact.irreducibles, x -> x{ factfus } );
zero := [ 1 .. Length( factfus ) ] * 0;
irr := sub.irreducibles;
newirr := [];
for entry in plan do
# Note that `proj' need not be dense.
sum:= Sum( irr{ entry } );
chi:= ShallowCopy( zero );
for i in [ 1 .. Length( chi ) ] do
if IsBound( proj[i] ) then
chi[i]:= sum[ proj[i] ];
fi;
od;
Add( newirr, chi );
od;
Append( irreds, newirr );
tbl.irreducibles:= Permuted( irreds, perm );
end;
#############################################################################
##
#F ConstructProj( <tbl>, <irrinfo> )
##
## constructs irreducibles for projective tables from projectives of
## a factor group table.
##
ConstructProj := function( tbl, irrinfo )
local i, j, factor, fus, mult, irreds, linear, omegasquare, I,
d, name, factfus, proj, adjust, Adjust,
ext, lin, chi, faith, nccl, partner, divs, prox, foll,
vals;
nccl:= Length( tbl.centralizers );
factor:= CharTable( irrinfo[1][1] );
fus:= GetFusionMap( tbl, factor );
mult:= tbl.centralizers[1] / factor.centralizers[1];
irreds:= List( factor.irreducibles, x -> x{ fus } );
linear:= Filtered( irreds, x -> x[1] = 1 );
linear:= Filtered( linear, x -> ForAny( x, y -> y <> 1 ) );
# some roots of unity
omegasquare:= E(3)^2;
I:= E(4);
# Loop over the divisors of 'mult' (a divisor of 12).
# Note the succession for 'mult = 12'!
if mult <> 12 then
divs:= Difference( DivisorsInt( mult ), [ 1 ] );
else
divs:= [ 2, 4, 3, 6, 12 ];
fi;
for d in divs do
# Construct the faithful irreducibles for an extension by 'd'.
# For that, we split and adjust the portion of characters (stored
# on the small table 'factor') as if we would create this extension,
# and then we blow up these characters to the whole table.
name:= irrinfo[d][1];
partner:= irrinfo[d][2];
proj:= First( factor.projectives, x -> x.name = name );
faith:= List( proj.chars, y -> y{ fus } );
proj:= Copy( proj.map );
if name = tbl.identifier then
factfus:= [ 1 .. Length( tbl.centralizers ) ];
else
factfus:= First( tbl.fusions, x -> x.name = name ).map;
fi;
Add( proj, Length( factfus ) + 1 ); # for termination of loop
adjust:= [];
for i in [ 1 .. Length( proj ) - 1 ] do
for j in [ proj[i] .. proj[i+1]-1 ] do
adjust[ j ]:= proj[i];
od;
od;
# now we have to multiply the values on certain classes 'j' with
# roots of unity, dependent on the value of 'd'\:
Adjust:= [];
for i in [ 1 .. d-1 ] do
Adjust[i]:= Filtered( [ 1 .. Length( factfus ) ],
x -> adjust[ factfus[x] ] = factfus[x] - i );
od;
# d = 2\:\ classes in 'Adjust[1]' multiply with '-1'
# d = 3\:\ classes in 'Adjust[x]' multiply
# with 'E(3)^x' for the proxy cohort,
# with 'E(3)^(2*x)' for the follower cohort
# d = 4\:\ classes in 'Adjust[x]' multiply
# with 'E(4)^x' for the proxy cohort,
# with '(-E(4))^x' for the follower cohort,
# d = 6\:\ classes in 'Adjust[x]' multiply with '(-E(3))^x'
# d = 12\:\ classes in 'Adjust[x]' multiply with '(E(12)^7)^x'
#
# (*Note* that follower cohorts of classes never occur in projective
# ATLAS tables ... )
# determine proxy classes and follower classes\:
if Length( linear ) in [ 2, 5 ] then # out in [ 3, 6 ]
prox:= [];
foll:= [];
chi:= irreds[ Length( linear ) ];
for i in [ 1 .. nccl ] do
if chi[i] = omegasquare then
Add( foll, i );
else
Add( prox, i );
fi;
od;
elif Length( linear ) = 3 then # out = 4
prox:= [];
foll:= [];
chi:= irreds[2];
for i in [ 1 .. nccl ] do
if chi[i] = -I then Add( foll, i ); else Add( prox, i ); fi;
od;
else
prox:= [ 1 .. nccl ];
foll:= [];
fi;
if d = 2 then
# special case without Galois partners
for chi in faith do
for i in Adjust[1] do chi[i]:= - chi[i]; od;
Add( irreds, chi );
for lin in linear do
ext:= List( [ 1 .. nccl ], x -> lin[x] * chi[x] );
if not ext in irreds then Add( irreds, ext ); fi;
od;
od;
elif d = 12 then
# special case with three Galois partners and 'lin = []'
vals:= [ E(12)^7, - omegasquare, - I, E(3), E(12)^11, -1,
-E(12)^7, omegasquare, I, -E(3), -E(12)^11 ];
for j in [ 1 .. Length( faith ) ] do
chi:= faith[j];
for i in [ 1 .. 11 ] do
chi{ Adjust[i] }:= vals[i] * chi{ Adjust[i] };
od;
Add( irreds, chi );
for i in partner[j] do
Add( irreds, List( chi, x -> GaloisCyc( x, i ) ) );
od;
od;
else
if d = 3 then
Adjust{ [ 1, 2 ] }:= [ Union( Intersection( Adjust[1], prox ),
Intersection( Adjust[2], foll ) ),
Union( Intersection( Adjust[2], prox ),
Intersection( Adjust[1], foll ) ) ];
vals:= [ E(3), E(3)^2 ];
elif d = 4 then
Adjust{ [ 1, 3 ] }:= [ Union( Intersection( Adjust[1], prox ),
Intersection( Adjust[3], foll ) ),
Union( Intersection( Adjust[3], prox ),
Intersection( Adjust[1], foll ) ) ];
vals:= [ I, -1, -I ];
elif d = 6 then
vals:= [ -E(3), omegasquare, -1, E(3), - omegasquare ];
fi;
for j in [ 1 .. Length( faith ) ] do
chi:= faith[j];
for i in [ 1 .. d-1 ] do
chi{ Adjust[i] }:= vals[i] * chi{ Adjust[i] };
od;
Add( irreds, chi );
for lin in linear do
ext:= List( [ 1 .. nccl ], x -> lin[x] * chi[x] );
if not ext in irreds then Add( irreds, ext ); fi;
od;
chi:= List( chi, x -> GaloisCyc( x, partner[j] ) );
Add( irreds, chi );
for lin in linear do
ext:= List( [ 1 .. nccl ], x -> lin[x] * chi[x] );
if not ext in irreds then Add( irreds, ext ); fi;
od;
od;
fi;
od;
tbl.irreducibles:= irreds;
end;
#############################################################################
##
#F ConstructDirectProduct( <tbl>, <factors> )
#F ConstructDirectProduct( <tbl>, <factors>, <permclasses>, <permchars> )
##
## special case of a 'construction' call for a library table <tbl>\:
##
## constructs a direct product of the tables described in the list
## <factors>, stores all those of its record components in <tbl>
## that are not yet bound in <tbl>.
## The 'fusions' component of <tbl> will be enlarged by the fusions of the
## direct product (factor fusions).
##
## If the optional arguments <permclasses>, <permchars> are given then
## classes and characters of the result are sorted accordingly.
##
ConstructDirectProduct := function( arg )
local tbl, factors, t, i, fld;
tbl:= arg[1];
factors:= arg[2];
t:= CharTableLibrary( factors[1] );
for i in [ 2 .. Length( factors ) ] do
t:= CharTableDirectProduct( t, CharTableLibrary( factors[i] ) );
od;
if 2 < Length( arg ) then
SortClassesCharTable( t, arg[3] );
SortCharactersCharTable( t, arg[4] );
Unbind( t.permutation );
fi;
for fld in Difference( RecFields( t ), RecFields( tbl ) ) do
tbl.( fld ):= t.( fld );
od;
if 1 < Length( factors ) then
Append( tbl.fusions, t.fusions );
fi;
end;
#############################################################################
##
#F ConstructIsoclinic( <tbl>, <factors>[, <nsg>[, <centre>]]
#F [, <permclasses>, <permchars>] )
##
ConstructIsoclinic := function( arg )
local tbl, factors, t, i, args, perms, fld;
tbl:= arg[1];
factors:= arg[2];
t:= CharTableLibrary( factors[1] );
for i in [ 2 .. Length( factors ) ] do
t:= CharTableDirectProduct( t, CharTableLibrary( factors[i] ) );
od;
args:= Filtered( arg, x -> not IsPerm( x ) );
if Length( args ) = 2 then
t:= CharTableIsoclinic( t );
elif Length( args ) = 3 then
t:= CharTableIsoclinic( t, args[3] );
elif Length( args ) = 4 then
t:= CharTableIsoclinic( t, args[3], args[4] );
else
Error( "invalid arguments <arg>" );
fi;
perms:= Filtered( arg, IsPerm );
if Length( perms ) = 2 then
SortClassesCharTable( t, perms[1] );
SortCharactersCharTable( t, perms[2] );
fi;
for fld in RecFields( t ) do
if not IsBound( tbl.( fld ) ) then
tbl.( fld ):= t.( fld );
fi;
od;
end;
#############################################################################
##
#F ConstructV4G( <tbl>, <facttbl>, <aut> )
##
## Let <tbl> be the character table of a group of type $2^2.G$
## where an outer automorphism of order 3 permutes the three involutions
## in the central $2^2$.
## Let <aut> be the permutation of classes of <tbl> induced by that
## automorphism, and <facttbl> the name of the character table
## of the factor group $2.G$.
## Then 'ConstructV4G' constructs the irreducible characters of <tbl> from
## that information.
##
ConstructV4G := function( arg )
local tbl, facttbls, aut, ker, fus, i, chars;
tbl:= arg[1];
if Length( arg ) = 2 then
facttbls:= arg[2];
else
facttbls:= [ arg[2] ];
aut:= arg[3];
fi;
fus:= List( facttbls, x -> First( tbl.fusions,
fus -> fus.name = x ).map );
facttbls:= List( facttbls, CharTable );
tbl.irreducibles:= List( facttbls[1].irreducibles, x -> x{ fus[1] } );
if Length( arg ) = 2 then
for i in [ 2 .. Length( facttbls ) ] do
Append( tbl.irreducibles, Filtered( List( facttbls[i].irreducibles,
x -> x{ fus[i] } ),
x -> not x in tbl.irreducibles ) );
od;
else
ker:= KernelChar( fus[1] );
ker:= Difference( OnTuples( ker, aut ), ker )[1];
chars:= List( Filtered( tbl.irreducibles, x -> x[1] <> x[ ker ] ),
x -> Permuted( x, aut ) );
Append( tbl.irreducibles, chars );
Append( tbl.irreducibles, List( chars, x -> Permuted( x, aut ) ) );
fi;
end;
#############################################################################
##
#F ConstructGS3( <tbls3>, <tbl2>, <tbl3>, <ind2>, <ind3>, <ext>, <perm> )
##
## constructs the irreducibles of a table <tbls3> of type $G.S_3$ from the
## tables <tbl2> and <tbl3> of $G.2$ and $G.3$, respectively.
## <ind2> is a list of numbers denoting irreducibles of <tbl2>.
## <ind3> is a list of pairs, each denoting irreducibles of <tbl3>.
## <ext> is a list of pairs, each denoting one irreducible of <tbl2>
## and one of <tbl3>.
## <perm> is a permutation that must be applied to the irreducibles.
##
ConstructGS3 := function( tbls3, tbl2, tbl3, ind2, ind3, ext, perm )
local fus2, # fusion map 'tbl2' in 'tbls3'
fus3, # fusion map 'tbl3' in 'tbls3'
proj2, # projection $G.S3$ to $G.2$
pos, # position in 'proj2'
proj2i, # inner part of projection $G.S3$ to $G.2$
proj2o, # outer part of projection $G.S3$ to $G.2$
proj3, # projection $G.S3$ to $G.3$
zeroon2, # zeros for part of $G.2 \setminus G$ in $G.S_3$
irr, # irreducible characters of 'tbls3'
i, # loop over 'ind2'
pair, # loop over 'ind3' and 'ext'
chi, # character
chii, # inner part of character
chio; # outer part of character
tbl2:= CharTable( tbl2 );
tbl3:= CharTable( tbl3 );
fus2:= GetFusionMap( tbl2, tbls3 );
fus3:= GetFusionMap( tbl3, tbls3 );
proj2:= ProjectionMap( fus2 );
pos:= First( [ 1 .. Length( proj2 ) ], x -> not IsBound( proj2[x] ) );
proj2i:= proj2{ [ 1 .. pos-1 ] };
pos:= First( [ pos .. Length( proj2 ) ], x -> IsBound( proj2[x] ) );
proj2o:= proj2{ [ pos .. Length( proj2 ) ] };
proj3:= ProjectionMap( fus3 );
zeroon2:= Difference( [ 1 .. Length( tbls3.centralizers ) ], fus3 ) * 0;
irr:= [];
# Induce the characters given by 'ind2' from 'tbl2'.
Append( irr, Induced( tbl2, tbls3, tbl2.irreducibles{ ind2 } ) );
# Induce the characters given by 'ind3' from 'tbl3'.
for pair in ind3 do
chi:= Sum( pair, x -> tbl3.irreducibles[x] );
Add( irr, Concatenation( chi{ proj3 }, zeroon2 ) );
od;
# Put the extensions from 'tbl' together.
for pair in ext do
chii:= tbl3.irreducibles[ pair[1] ]{ proj3 };
chio:= tbl2.irreducibles[ pair[2] ]{ proj2o };
Add( irr, Concatenation( chii, chio ) );
Add( irr, Concatenation( chii, -chio ) );
od;
# Permute the characters with 'perm'.
irr:= Permuted( irr, perm );
# Store the irreducibles.
tbls3.irreducibles:= irr;
end;
#############################################################################
##
#F ConstructPermuted( <tbl>, <libnam>[, <prmclasses>, <prmchars>] )
##
## The library table <tbl> is completed with help of the library table with
## name <libnam>, whose classes and characters must be permuted by the
## permutations <prmclasses> and <prmchars>, respectively.
##
ConstructPermuted := function( arg )
local tbl, t, fld, automorphisms, irredinfo, classtext, fusions,
projectives;
tbl:= arg[1];
t := CharTableLibrary( arg[2] );
for fld in RecFields( t ) do
if not IsBound( tbl.( fld ) ) then
tbl.(fld) := t.(fld);
fi;
od;
if IsBound( tbl.automorphisms ) then
automorphisms:= tbl.automorphisms;
Unbind( tbl.automorphisms );
fi;
if IsBound( tbl.irredinfo ) then
irredinfo:= tbl.irredinfo;
Unbind( tbl.irredinfo );
fi;
if IsBound( tbl.classtext ) then
classtext:= tbl.classtext;
Unbind( tbl.classtext );
fi;
if IsBound( tbl.fusions ) then
fusions:= tbl.fusions;
tbl.fusions:= [];
fi;
if IsBound( tbl.projectives ) then
projectives:= tbl.projectives;
Unbind( tbl.projectives );
fi;
if 2 < Length( arg ) then
SortClassesCharTable( tbl, arg[3] );
fi;
if 3 < Length( arg ) then
SortCharactersCharTable( tbl, arg[4] );
fi;
Unbind( tbl.permutation );
if IsBound( automorphisms ) then
tbl.automorphisms:= automorphisms;
fi;
if IsBound( irredinfo ) then
tbl.irredinfo:= irredinfo;
fi;
if IsBound( classtext ) then
tbl.classtext:= classtext;
fi;
if IsBound( fusions ) then
tbl.fusions:= fusions;
fi;
if IsBound( projectives ) then
tbl.projectives:= projectives;
fi;
end;
#############################################################################
##
#F ConstructAdjusted( <tbl>, <libnam>, <pairs>
#F [, <permclasses>, <permchars>] )
##
ConstructAdjusted:= function( arg )
local tbl, t, pair;
tbl:= arg[1];
# Get the permuted library table.
t:= CharTableLibrary( arg[2] );
if 3 < Length( arg ) and arg[4] <> () then
SortClassesCharTable( t, arg[4] );
fi;
if 4 < Length( arg ) and arg[5] <> () then
SortCharactersCharTable( t, arg[5] );
fi;
# Set the components that shall be adjusted.
for pair in arg[3] do
if pair[1] = "ComputedPowerMaps" then
tbl.powermaps:= pair[2];
else
Error( "transfer of component `", pair[1],
"' is not yet supported by `ConstructAdjusted'" );
fi;
od;
# Transfer not adjusted defining components.
if not IsBound( tbl.centralizers ) then
tbl.centralizers:= t.centralizers;
fi;
if not IsBound( tbl.powerpaps ) then
tbl.powermap:= t.powermap;
fi;
if not IsBound( tbl.irreducibles ) then
tbl.irreducibles:= t.irreducibles;
fi;
end;
#############################################################################
##
#F ConstructFactor( <tbl>, <libnam>, <kernel> )
##
## The library table <tbl> is completed with help of the library table with
## name <libnam>, whose classes and characters must be permuted by the
## permutations <prmclasses> and <prmchars>, respectively.
##
ConstructFactor := function( tbl, libnam, kernel )
local t, fld;
t:= CharTableFactorGroup( CharTableLibrary( libnam ), kernel );
for fld in RecFields( t ) do
if not IsBound( tbl.( fld ) ) then
tbl.(fld) := t.(fld);
fi;
od;
end;
#############################################################################
##
#F ConstructSubdirect( <tbl>, <factors>, <choice> )
##
## The library table <tbl> is completed with help of the table got from
## taking the direct product of the tables with names in the list <factors>,
## and then taking the table consisting of the classes in the list <choice>.
##
ConstructSubdirect := function( tbl, factors, choice )
local t, i, fld;
t:= CharTableLibrary( factors[1] );
for i in [ 2 .. Length( factors ) ] do
t:= CharTableDirectProduct( t, CharTableLibrary( factors[i] ) );
od;
t:= CharTableNormalSubgroup( t, choice );
for fld in RecFields( t ) do
if not IsBound( tbl.( fld ) ) then
tbl.( fld ):= t.( fld );
fi;
od;
end;
#############################################################################
##
#F IrreducibleCharactersOfIndexTwoSubdirectProduct( <irrH1xH2>, <irrG1xG2>,
#F <H1xH2fusG>, <GfusG1xG2> )
##
## We do not want to use the table head of the subdirect product because
## this function is also called by `ConstructIndexTwoSubdirectProduct',
## and there just a record is available from which the table is computed
## later.
##
IrreducibleCharactersOfIndexTwoSubdirectProduct:=
function( irrH1xH2, irrG1xG2, H1xH2fusG, GfusG1xG2 )
local H1xH2fusG1xG2, restpos, i, rest, pos, irr, zero, proj1, perm,
proj2, chi, ind, j;
H1xH2fusG1xG2:= CompositionMaps( GfusG1xG2, H1xH2fusG );
# Compute which irreducibles of H1xH2 extend to G1xG2.
restpos:= List( irrH1xH2, x -> [] );
for i in [ 1 .. Length( irrG1xG2 ) ] do
rest:= irrG1xG2[i]{ H1xH2fusG1xG2 };
pos:= Position( irrH1xH2, rest );
if pos <> false then
Add( restpos[ pos ], i );
fi;
od;
irr:= [];
zero:= 0 * GfusG1xG2;
proj1:= ProjectionMap( H1xH2fusG );
perm:= Product( List( Filtered( InverseMap( H1xH2fusG ), IsList ),
l -> ( l[1], l[2] ) ) );
if perm = 1 then
perm:= ();
fi;
proj2:= [];
for i in [ 1 .. Length( proj1 ) ] do
if IsBound( proj1[i] ) then
proj2[i]:= proj1[i]^perm;
fi;
od;
for i in [ 1 .. Length( irrH1xH2 ) ] do
if not IsEmpty( restpos[i] ) then
# The i-th irreducible of H1xH2 extends to G1xG2.
# Restrict these extensions to G.
Append( irr, DuplicateFreeList( List( irrG1xG2{ restpos[i] },
chi -> chi{ GfusG1xG2 } ) ) );
else
# The i-th irreducible character of H1xH2 has inertia subgroup one of
# H1xG2 or G1xH2, so it induces irreducibly to G.
# Compute the induced character (without using the table head).
chi:= irrH1xH2[i];
# The curly bracket operator works only for dense sublists.
# ind:= ShallowCopy( zero ) + chi{ proj1 } + chi{ proj2 };
ind:= ShallowCopy( zero );
for j in [ 1 .. Length( proj1 ) ] do
if IsBound( proj1[j] ) then
ind[j]:= ind[j] + chi[ proj1[j] ];
fi;
od;
for j in [ 1 .. Length( proj2 ) ] do
if IsBound( proj2[j] ) then
ind[j]:= ind[j] + chi[ proj2[j] ];
fi;
od;
if not ind in irr then
Add( irr, ind );
fi;
fi;
od;
return irr;
end;
#############################################################################
##
#F ClassFusionsForIndexTwoSubdirectProduct( <tblH1>, <tblG1>, <tblH2>,
#F <tblG2> )
##
## It is assumed that all tables are either ordinary tables or Brauer tables
## for the same characteristic.
##
## Note that the components `GfusG1xG2', `Gclasses', `Gorders' refer only to
## the classes inside the normal subgroup `<tblH1> * <tblH2>'.
##
ClassFusionsForIndexTwoSubdirectProduct:= 0;
ClassFusionsForIndexTwoSubdirectProduct:=
function( tblH1, tblG1, tblH2, tblG2 )
local p, H1classes, H2classes, H1orders, H2orders, H1fusG1, H2fusG2,
inv1, inv2, ncclH2, ncclG2, H1xH2fusG, GfusG1xG2,
Gclasses, Gorders, i1, i2, posG1xG2, len, pos,
ordH1, ordG1, ordH2, ordG2, info, modGfusordG, modfus2,
modG1xG2fusordG1xG2, modH1xH2fusordH1xH2;
if IsBound( tblH1.prime ) then
p:= tblH1.prime;
else
p:= 0;
fi;
if p = 0 then
H1classes:= tblH1.classes;
H2classes:= tblH2.classes;
H1orders:= tblH1.orders;
H2orders:= tblH2.orders;
H1fusG1:= GetFusionMap( tblH1, tblG1 );
if H1fusG1 = false then
H1fusG1:= RepresentativesFusions( tblH1,
SubgroupFusions( tblH1, tblG1 ), tblG1 );
if Length( H1fusG1 ) <> 1 then
Error( "fusion <tblH1> to <tblG1> is not determined" );
fi;
fi;
H2fusG2:= GetFusionMap( tblH2, tblG2 );
if H2fusG2 = false then
H2fusG2:= RepresentativesFusions( tblH2,
SubgroupFusions( tblH2, tblG2 ), tblG2 );
if Length( H2fusG2 ) <> 1 then
Error( "fusion <tblH2> to <tblG2> is not determined" );
fi;
fi;
inv1:= InverseMap( H1fusG1 );
inv2:= InverseMap( H2fusG2 );
ncclH2:= Length( H2classes );
ncclG2:= Length( tblG2.classes );
H1xH2fusG:= [];
GfusG1xG2:= [];
Gclasses:= [];
Gorders:= [];
for i1 in [ 1 .. Length( inv1 ) ] do
if IsBound( inv1[ i1 ] ) then
for i2 in [ 1 .. Length( inv2 ) ] do
if IsBound( inv2[ i2 ] ) then
posG1xG2:= ( i1 - 1 ) * ncclG2 + i2;
if IsInt( inv1[ i1 ] ) then
if IsInt( inv2[ i2 ] ) then
# no fusion
len:= Length( GfusG1xG2 ) + 1;
H1xH2fusG[ ( inv1[ i1 ] - 1 ) * ncclH2 + inv2[ i2 ] ]:= len;
GfusG1xG2[ len ]:= posG1xG2;
Gclasses[ len ]:= H1classes[ inv1[ i1 ] ]
* H2classes[ inv2[ i2 ] ];
Gorders[ len ]:= LcmInt( H1orders[ inv1[ i1 ] ],
H2orders[ inv2[ i2 ] ] );
else
# fusion from H2 to G2
len:= Length( GfusG1xG2 ) + 1;
for pos in inv2[ i2 ] do
H1xH2fusG[ ( inv1[ i1 ] - 1 ) * ncclH2 + pos ]:= len;
od;
GfusG1xG2[ len ]:= posG1xG2;
Gclasses[ len ]:= 2 * H1classes[ inv1[ i1 ] ]
* H2classes[ inv2[ i2 ][1] ];
Gorders[ len ]:= LcmInt( H1orders[ inv1[ i1 ] ],
H2orders[ inv2[ i2 ][1] ] );
fi;
elif IsInt( inv2[ i2 ] ) then
# fusion from H1 to G1
len:= Length( GfusG1xG2 ) + 1;
for pos in inv1[ i1 ] do
H1xH2fusG[ ( pos - 1 ) * ncclH2 + inv2[ i2 ] ]:= len;
od;
GfusG1xG2[ len ]:= posG1xG2;
Gclasses[ len ]:= 2 * H1classes[ inv1[ i1 ][1] ]
* H2classes[ inv2[ i2 ] ];
Gorders[ len ]:= LcmInt( H1orders[ inv1[ i1 ][1] ],
H2orders[ inv2[ i2 ] ] );
else
# fusion in both factors (get two classes)
len:= Length( GfusG1xG2 ) + 1;
H1xH2fusG[ ( inv1[ i1 ][1]-1 ) * ncclH2 + inv2[i2][1] ]:= len;
H1xH2fusG[ ( inv1[ i1 ][2]-1 ) * ncclH2 + inv2[i2][2] ]:= len;
GfusG1xG2[ len ]:= posG1xG2;
Gclasses[ len ]:= 2 * H1classes[ inv1[ i1 ][1] ]
* H2classes[ inv2[ i2 ][1] ];
Gorders[ len ]:= LcmInt( H1orders[ inv1[ i1 ][1] ],
H2orders[ inv2[ i2 ][1] ] );
H1xH2fusG[ ( inv1[i1][1]-1 ) * ncclH2 + inv2[i2][2] ]:= len + 1;
H1xH2fusG[ ( inv1[i1][2]-1 ) * ncclH2 + inv2[i2][1] ]:= len + 1;
GfusG1xG2[ len + 1 ]:= posG1xG2;
Gclasses[ len + 1 ]:= Gclasses[ len ];
Gorders[ len + 1 ]:= Gorders[ len ];
fi;
fi;
od;
fi;
od;
else
ordH1:= tblH1.ordinary;
ordG1:= tblG1.ordinary;
ordH2:= tblH2.ordinary;
ordG2:= tblG2.ordinary;
# Compute the maps for the underlying ordinary tables.
info:= ClassFusionsForIndexTwoSubdirectProduct( ordH1, ordG1,
ordH2, ordG2 );
# Compute the embeddings of `p'-regular classes of G, H1xH2, G1xG2,
# without actually constructing these tables.
modGfusordG:= Filtered( [ 1 .. Length( info.Gorders ) ],
i -> info.Gorders[i] mod p <> 0 );
modfus2:= GetFusionMap( tblG2, ordG2 );
modG1xG2fusordG1xG2:= Concatenation(
List( GetFusionMap( tblG1, ordG1 ),
i -> modfus2 + ( i - 1 ) * Length( ordG2.classes ) ) );
modfus2:= GetFusionMap( tblH2, ordH2 );
modH1xH2fusordH1xH2:= Concatenation(
List( GetFusionMap( tblH1, ordH1 ),
i -> modfus2 + ( i - 1 ) * Length( ordH2.classes ) ) );
# Compute the maps for the Brauer tables.
H1xH2fusG:= CompositionMaps( InverseMap( modGfusordG ),
CompositionMaps( info.H1xH2fusG, modH1xH2fusordH1xH2 ) );
GfusG1xG2:= CompositionMaps( InverseMap( modG1xG2fusordG1xG2 ),
CompositionMaps( info.GfusG1xG2, modGfusordG ) );
Gclasses:= info.Gclasses{ modGfusordG };
Gorders:= info.Gorders{ modGfusordG };
fi;
return rec( H1xH2fusG:= H1xH2fusG,
GfusG1xG2:= GfusG1xG2,
Gclasses:= Gclasses,
Gorders:= Gorders
);
end;
#############################################################################
##
#F ConstructIndexTwoSubdirectProduct( <tbl>, <tblH1>, <tblG1>, <tblH2>,
#F <tblG2>, <outerfus>, <permclasses>, <permchars> )
##
ConstructIndexTwoSubdirectProduct:= function( tbl, tblH1, tblG1, tblH2, tblG2,
outerfus, permclasses, permchars )
local info, irreds;
tblH1:= CharTable( tblH1 );
tblG1:= CharTable( tblG1 );
tblH2:= CharTable( tblH2 );
tblG2:= CharTable( tblG2 );
info:= ClassFusionsForIndexTwoSubdirectProduct(
tblH1, tblG1, tblH2, tblG2 );
irreds:= IrreducibleCharactersOfIndexTwoSubdirectProduct(
KroneckerProduct( tblH1.irreducibles, tblH2.irreducibles ),
KroneckerProduct( tblG1.irreducibles, tblG2.irreducibles ),
info.H1xH2fusG, Concatenation( info.GfusG1xG2, outerfus ) );
tbl.irreducibles:= Permuted(
List( irreds, chi -> Permuted( chi, permclasses ) ),
permchars );
end;
#############################################################################
##
#F ConstructWreathSymmetric( <tbl>, <subname>, <n>
#F [, <permclasses>, <permchars>] )
##
ConstructWreathSymmetric:= function( arg )
local tbl, sub, t, fld;
tbl:= arg[1];
sub:= CharTableLibrary( arg[2] );
t:= CharTableWreathSymmetric( sub, arg[3] );
if 3 < Length( arg ) then
SortClassesCharTable( t, arg[4] );
SortCharactersCharTable( t, arg[5] );
if not IsBound( tbl.permutation ) then
# Do *not* inherit the permutation from the construction!
tbl.permutation:= ();
fi;
fi;
for fld in Difference( RecFields( t ), RecFields( tbl ) ) do
tbl.( fld ):= t.( fld );
od;
end;
#############################################################################
##
#F UnpackedCll( <cll> )
##
## is a record with the components 'mat', 'inertiagrps', 'fusionclasses',
## and perhaps 'libname'.
## These are the only components used in the construction of library
## character tables encoded by Clifford matrices.
##
## The meaning of <cll> is the same as in 'CllToClf'.
##
UnpackedCll := function( cll )
local l, clmlist, # library list of the possible matrices
clf, # Clifford matrix record, result
pi; # permutation to sort library matrices
# Initialize the Clifford matrix record.
clf:= rec(
inertiagrps := cll[1],
fusionclasses := cll[2]
);
if Length( cll[2] ) = 1 then
clf.mat:= [ [ 1 ] ];
elif Length( cll[3] ) = 2 then
# is already unpacked, for example dimension 2
clf.mat:= cll[3];
else
# Fetch the matrix from the library.
cll:= cll[3];
clf.libname:= cll;
l:= cll[2];
clmlist:= LibraryTables( Concatenation( "clm", cll[1] ) );
if clmlist = false or not IsBound( clmlist[l] ) then
Error( "sorry, component <mat> not found in the library" );
fi;
clf.mat:= Copy( clmlist[l][ cll[3] ] );
# Sort the rows and columns of the Clifford matrix
# w.r.t. the explicitly given permutations.
if IsBound( cll[4] ) then
clf.mat:= Permuted( clf.mat, cll[4] );
fi;
if IsBound( cll[5] ) then
pi:= cll[5];
clf.mat:= List( clf.mat, x -> Permuted( x, pi ) );
fi;
fi;
return clf;
end;
#############################################################################
##
#F CllToClf( <tbl>, <cll> )
##
## is a Clifford matrix for the table <tbl>.
## It is constructed from the list <cll> that contains
## the following entries.
## 1. list of indices of inertia factors
## 2. list of classes fusing in the factor group
## 3. identification of the matrix,
## either unbound (then the matrix has dimension <= 2)
## or a list containing
## a. string '"elab"' or '"exsp"'
## b. size of the Clifford matrix
## c. index in the library file
## d. (optional) necessary permutation of columns
## or a list containing
## a. the Clifford matrix itself and
## b. the column weights.
## 4. (case '"exsp"') a list with items of record 'splitinfos':
## a. classindex
## b. p
## c. numclasses
## d. root
##
CllToClf := function( tbl, cll )
local Ti, #
factor, # character table of the factor group G/N
i, nr,
dim, # dimension of the matrix
clf, # expanded record
pos,
map;
Ti:= tbl.cliffordTable.Ti;
factor:= Ti.tables[1];
if not IsBound( factor.classnames ) then
ClassNamesCharTable( factor );
fi;
nr:= cll[2][1];
dim:= Length( cll[2] );
# Decode 'cll'.
clf:= UnpackedCll( cll );
# Fill the Clifford matrix record.
clf.nr := nr;
clf.size := dim;
clf.order := factor.orders[nr];
clf.orders := [ factor.orders[nr] ];
clf.elname := factor.classnames[nr];
clf.full := true;
# Compute the row weights $b_a = |C_{T_m/N}(gN)|$.
clf.roww:= List( [ 1 .. dim ],
i -> Ti.tables[ cll[1][i] ].centralizers[ cll[2][i] ] );
# Compute the column weights $m_k = |Cl_{G/N}(gN)| / |Cl_G(g_k)|$.
pos:= 0;
for map in Ti.fusions do
pos:= pos + Number( map, x -> x < nr );
od;
clf.colw:= List( [ 1 .. dim ],
i -> tbl.classes[ pos+i ] / factor.classes[nr] );
# if dim = 1 then
# if IsBound( cll[4] ) then
# clf.colw := [cll[4][2]];
# else
# clf.colw := [1];
# #T ??
# fi;
# elif dim = 2 then
#
# factor:= Ti.tables[ clf.inertiagrps[2] ];
# if not IsCharTable( factor ) then
# factor:= CharTableLibrary( factor );
# fi;
#
# if IsBound( cll[4] ) then
# if cll[4][1] = 0 then #not really splitted
# clf.colw := cll[4][2]*[1, clf.roww[1]/clf.roww[2]];
# clf.mat:= [[1,1],[clf.roww[1]/clf.roww[2],-1]];
# else
# clf.colw := [ 1, cll[4][2]-1 ];
# clf.mat:= [[1,1],[cll[4][4]*clf.colw[2],-cll[4][4]]];
# fi;
# else
# clf.colw := [1, clf.roww[1]/clf.roww[2]];
# clf.mat:= [[1,1],[clf.colw[2],-1]];
# #T but this holds only for split cosets!
# fi;
# fi;
# Handle the special case of extraspecial groups.
if Length( cll ) = 4 then
clf.splitinfos:= rec( classindex := cll[4][1],
p := cll[4][2] );
if IsBound( cll[4][3] ) then
clf.splitinfos.numclasses:= cll[4][3];
fi;
if IsBound( cll[4][4] ) then
clf.splitinfos.root:= cll[4][4];
fi;
fi;
return clf;
end;
#############################################################################
##
#F ConstructClifford( <tbl>, <cliffordtable> )
##
## constructs the irreducibles of the ordinary character table <tbl> from
## the Clifford matrices stored in '<tbl>.cliffordTable'.
##
ConstructClifford := function( tbl, cliffordTable )
local i, j, n,
AnzTi,
tables,
ct, # list of lists of relevant characters,
# one for each inertia factor group
clmexp,
clmat,
matsize,
grps,
newct, # the list of irreducibles of 'tbl'
rowct, # actual row
colct, # actual column
eintr,
chars,
linear,
chi, # loop over a character list
lin,
new;
# Decode the 'cliffordTable' component of 'tbl'.
cliffordTable:= rec( Ti:= rec( fusions:= cliffordTable[1],
tables := cliffordTable[2] ),
cliffordrecords:= cliffordTable[3] );
cliffordTable.Ti.ident:= Copy( cliffordTable.Ti.tables );
# Get the character tables of the inertia groups,
# and store the relevant list of characters.
tables:= cliffordTable.Ti.tables;
AnzTi:= Length( tables );
ct:= [];
for i in [ 1 .. AnzTi ] do
if tables[i][1] = "projectives" then
eintr:= CharTableLibrary( [ tables[i][2] ] );
else
eintr:= CharTableLibrary( tables[i] );
fi;
if eintr = false then
Error( "table of inertia factor group '", tables[i],
"' not in the library" );
fi;
if tables[i][1] = "projectives" then
# We must multiply the stored projectives with all linear characters
# of the factor group in order to get the full list.
chars:= First( eintr.projectives, x -> x.name = tables[i][3] ).chars;
ct[i]:= [];
linear:= Filtered( eintr.irreducibles, x -> x[1] = 1 );
n:= Length( eintr.irreducibles );
for chi in chars do
for lin in linear do
new:= List( [ 1 .. n ], x -> chi[x] * lin[x] );
if not new in ct[i] then
Add( ct[i], new );
fi;
od;
od;
else
ct[i]:= eintr.irreducibles;
fi;
tables[i]:= eintr;
od;
# Construct the matrix of irreducibles characters.
newct := List( tbl.centralizers, x -> [] );
colct := 0;
for i in cliffordTable.cliffordrecords do
# Get the necessary components of the 'i'-th Clifford matrix,
# and multiply it with the character tables of inertia factor groups.
clmexp := UnpackedCll( i );
clmat := clmexp.mat;
matsize := Length( clmat );
grps := clmexp.inertiagrps;
# Loop over the columns of the matrix.
for n in [ 1 .. matsize ] do
rowct := 0;
colct := colct + 1;
# Loop over the inertia factor groups.
for j in [ 1 .. AnzTi ] do
for chi in ct[j] do
rowct:= rowct + 1;
newct[rowct][colct]:= Sum( Filtered( [ 1 .. matsize ],
r -> grps[r] = j ),
x -> clmat[x][n] * chi[ clmexp.fusionclasses[x] ]);
od;
od;
od;
od;
tbl.irreducibles := newct;
end;
#############################################################################
##
#F BrauerTree( <decmat> )
##
## returns the Brauer tree of the block <decmat> of a decomposition matrix,
## if exists, and 'false' otherwise.
##
## The decomposition matrix must consist of 0 and 1 if a Brauer tree exists.
##
BrauerTree := function( decmat )
local i, j, brauertree, edge, len;
if not ( IsMat( decmat )
and ForAll( decmat, x -> ForAll( x, y -> y=0 or y=1 ) ) ) then
Print( "#I BrauerTree: <decmat> is not decomposition matrix\n",
"#I of a block of cyclic defect\n");
return false;
fi;
if decmat = [ [ 1 ] ] then return []; fi;
brauertree:= [];
for i in [ 1 .. Length( decmat[1] ) ] do
# find the entries 1 in column 'i'
edge:= [];
for j in [ 1 .. Length( decmat ) ] do
if decmat[j][i] = 1 then Add( edge, j ); fi;
od;
len:= Length( edge );
# If 'len = 2', we have an ordinary edge of the tree; else this may
# concern an exceptional character.
if len = 2 then
Add( brauertree, edge );
else
if Length( Set( decmat{ edge } ) ) <= 2 then
# all or all but one ordinary irreducibles restrict identically
Add( brauertree, edge );
else
Print( "#I BrauerTree: <decmat> is not decomposition",
" matrix\n",
"#I of a block of cyclic defect\n");
return false;
fi;
fi;
od;
return brauertree;
end;
#############################################################################
##
#F DecMat( <brauertree> )
##
## Technically, a Brauer tree is a list <brauertree> where '<brauertree>[i]'
## contains the positions of '1' in the 'i'-th column of the decomposition
## matrix of the corresponding block. So '<brauertree>[i]' has length 2 or
## 3 (in the case of exceptional characters).
##
## 'DecMat' returns the decomposition matrix of the block.
##
DecMat := function( brauertree )
local i, j, max, decmat;
max:= 1;
for i in brauertree do max:= Maximum( max, Maximum(i) ); od;
decmat:= NullMat( max, Length( brauertree ) );
for i in [ 1 .. Length( brauertree ) ] do
for j in brauertree[i] do decmat[j][i]:= 1; od;
od;
return decmat;
end;
#############################################################################
##
#F BasicSetBrauerTree( <brauertree> )
##
## returns a basic set of the Brauer tree <brauertree>.
## *Note* that this is a list of positions relative to the block, so it is
## not compatible with the 'basicset' entries of Brauer tables.
##
BasicSetBrauerTree := function( brauertree )
local i, degrees, basicset, edge, elm;
brauertree:= Set( brauertree );
basicset:= [];
# degrees of the vertices
degrees:= [];
for edge in brauertree do
for i in edge do
if not IsBound( degrees[i] ) then
degrees[i]:= 1;
else
degrees[i]:= degrees[i] + 1;
fi;
od;
od;
while brauertree <> [] do
# take a vertex of degree 1, remove its edge, adjust 'degrees'
elm:= Position( degrees, 1 );
AddSet( basicset, elm );
edge:= First( brauertree, x -> elm in x );
RemoveSet( brauertree, edge );
for i in edge do
degrees[i]:= degrees[i] - 1;
od;
od;
return basicset;
end;
#############################################################################
##
#F AddDecMats( <tbl> )
##
## stores decomposition matrices of blocks in the 'block' component of
## the Brauer table <tbl>
##
AddDecMats := function( tbl )
local fus, block, ordchars, modchars;
if not IsBound( tbl.blocks ) then
Error( "<tbl> must be a Brauer table" );
fi;
fus:= GetFusionMap( tbl, tbl.ordinary );
for block in tbl.blocks do
if block.defect = 0 then
block.decmat:= [ [ 1 ] ];
else
ordchars:= tbl.ordinary.irreducibles{ block.ordchars }{ fus };
modchars:= tbl.irreducibles{ block.modchars };
block.decmat:= Decomposition( modchars, ordchars, "nonnegative" );
fi;
od;
end;
#############################################################################
##
#F PartsBrauerTableName( <modname> )
##
## returns a record with components 'ordname' (substring up to the
## occurrence of 'mod' in <modname>) and 'prime' (the integer of the string
## after 'mod').
##
PartsBrauerTableName := function( modname )
local i, primestring, ordname, prime, digits;
primestring:= 0;
for i in [ 1 .. Length( modname ) - 2 ] do
if modname{ [ i .. i + 2 ] } = "mod" then
primestring:= modname{ [ i + 3 .. Length( modname ) ] };
ordname:= modname{ [ 1 .. i-1 ] };
fi;
od;
if primestring = 0 then
Print( "#I PartsBrauerTableName: ", modname,
" is no valid name\n",
"#I for a Brauer table\n" );
return false;
fi;
digits:= "0123456789";
primestring:= List( primestring, x -> Position( digits, x ) );
if false in primestring then
Print( "#I PartsBrauerTableName: ", modname,
" is no valid name\n",
"#I for a Brauer table\n" );
return false;
fi;
prime:= 0;
for i in [ 1 .. Length( primestring ) ] do
prime:= 10 * prime + ( primestring[i] - 1 );
od;
return rec( ordname:= ordname, prime:= prime );
end;
#############################################################################
##
#F BrauerTable( <name>, <ordtbl> )
##
## returns the Brauer table with name <name>.
## <ordtbl> is the corresponding ordinary table.
##
BrauerTable := function( name, ordtbl )
local parts, libtbl, i, j, ord, pow, reg, result, ordblocks, modblocks,
defect, prime, irreducibles, restricted, block, basicset,
class, images, chi, gal, newimages, pos, im, decmat,
brauertree, filename, facttbl, offset, decinv,
filename, fld;
if IsSolvable( ordtbl ) then
# In this case, 'CharTableOps.\mod' does not call 'BrauerTable'.
parts:= PartsBrauerTableName( name );
if parts <> false then
return ordtbl mod parts.prime;
fi;
fi;
filename:= LibInfoCharTable( name ).fileName;
fld:= LibraryTables( filename );
if fld = false or not IsBound( fld.( name ) ) then
Print("#E CharTable: no library table with name '",name,"'\n");
return false;
fi;
libtbl:= Copy( fld.( name ) );
libtbl.identifier:= name;
reg:= CharTableRegular( ordtbl, libtbl.prime );
prime:= libtbl.prime;
if not IsBound( libtbl.text ) then
libtbl.text:= "";
fi;
result:= rec(
identifier := libtbl.identifier,
text := libtbl.text,
prime := libtbl.prime,
size := reg.size,
centralizers := reg.centralizers,
orders := reg.orders,
classes := reg.classes,
powermap := reg.powermap,
fusions := [ rec( name:= ordtbl.identifier,
map := GetFusionMap( reg, ordtbl ),
type:= "choice" ) ],
irreducibles := [],
irredinfo := [],
blocks := [],
ordinary := ordtbl,
operations := BrauerTableOps );
result.order:= result.size;
result.name:= result.identifier;
#T just a hack ...
result.defect:= libtbl.defect;
result.block:= libtbl.block;
if IsBound( libtbl.decinv ) then
result.decinv:= libtbl.decinv;
fi;
if IsBound( libtbl.basicset ) then
result.basicset:= libtbl.basicset;
fi;
if IsBound( libtbl.brauertree ) then
result.brauertree:= libtbl.brauertree;
fi;
#T end of the hack ...
# if automorphisms are stored (as list of generators), convert to group
if IsBound( libtbl.automorphisms ) then
result.automorphisms:= Group( libtbl.automorphisms, () );
fi;
# complete the name change of 'reg'
RemoveSet( ordtbl.fusionsource, reg.identifier );
AddSet( ordtbl.fusionsource, libtbl.identifier );
# initialize some components
if not IsBound( libtbl.decinv ) then libtbl.decinv:= []; fi;
block:= [];
defect:= [];
basicset:= [];
brauertree:= [];
decinv:= [];
# If the distribution to blocks is stored on the table
# then use it, otherwise compute it.
ordblocks:= ordtbl.irredinfo;
if IsBound( ordblocks[1].pblock )
and IsBound( ordblocks[1].pblock[ prime ] ) then
ordblocks:= List( ordblocks, x -> x.pblock[ prime ] );
else
ordblocks:= PrimeBlocks( ordtbl, prime ).block;
fi;
ordblocks:= InverseMap( ordblocks );
# get the blocks of factor groups if necessary;
# 'factorblocks' is a list of pairs containing the names of the
# tables that hold the blocks and the offset of basic set characters
if IsBound( libtbl.factorblocks ) then
for i in libtbl.factorblocks do
facttbl:= Concatenation( i[1], "mod", String( libtbl.prime ) );
if IsBound( LIBTABLE.( filename ).( facttbl ) ) then
facttbl:= LIBTABLE.( filename ).( facttbl );
else
# The factor table is in another file (hopefully a rare case).
facttbl:= CharTableLibrary( [ facttbl ] );
fi;
if block = [] then
offset:= 0;
else
offset:= Maximum( block ) + 1 - Minimum( facttbl.block );
fi;
pos:= Length( defect );
Append( defect, Copy( facttbl.defect ) );
Append( block, offset + facttbl.block );
for j in [ 1 .. Length( facttbl.defect ) ] do
if facttbl.defect[j] <> 0 then
if IsBound( facttbl.decinv ) and
IsBound( facttbl.decinv[j] ) then
if IsInt( facttbl.decinv[j] ) then
decinv[ pos + j ]:=
Copy( facttbl.decinv[ facttbl.decinv[j] ] );
else
decinv[ pos + j ]:= Copy( facttbl.decinv[j] );
fi;
brauertree[ pos + j ]:= false;
basicset[ pos + j ]:= i[2] + facttbl.basicset[j];
else
if IsInt( facttbl.brauertree[j] ) then
brauertree[ pos + j ]:=
Copy( facttbl.brauertree[ facttbl.brauertree[j] ] );
else
brauertree[ pos + j ]:= facttbl.brauertree[j];
fi;
basicset[ pos + j ]:= ordblocks[ pos + j ]{
BasicSetBrauerTree( brauertree[ pos + j ] ) };
fi;
fi;
od;
od;
fi;
pos:= Length( defect );
Append( defect, libtbl.defect );
Append( block, libtbl.block );
for j in [ 1 .. Length( libtbl.defect ) ] do
if libtbl.defect[j] <> 0 then
if IsBound( libtbl.decinv[j] ) then
if IsInt( libtbl.decinv[j] ) then
decinv[ pos + j ]:= Copy( libtbl.decinv[ libtbl.decinv[j] ] );
else
decinv[ pos + j ]:= Copy( libtbl.decinv[j] );
fi;
brauertree[ pos + j ]:= false;
basicset[ pos + j ]:= libtbl.basicset[j];
else
if IsInt( libtbl.brauertree[j] ) then
brauertree[ pos + j ]:=
Copy( libtbl.brauertree[ libtbl.brauertree[j] ] );
else
brauertree[ pos + j ]:= libtbl.brauertree[j];
fi;
basicset[ pos + j ]:= ordblocks[ pos + j ]{
BasicSetBrauerTree( brauertree[ pos + j ] ) };
fi;
fi;
od;
# compute the blocks and the irreducibles of each block,
# and assign them to the right positions;
# assign the known decomposition matrices and Brauer trees;
# ignore defect 0 blocks
irreducibles:= [];
restricted:= Restricted( ordtbl, reg, ordtbl.irreducibles );
modblocks := InverseMap( block );
for i in [ 1 .. Length( ordblocks ) ] do
if IsInt( ordblocks[i] ) then ordblocks[i]:= [ ordblocks[i] ]; fi;
if IsInt( modblocks[i] ) then modblocks[i]:= [ modblocks[i] ]; fi;
if defect[i] = 0 then
irreducibles[ modblocks[i][1] ]:= restricted[ ordblocks[i][1] ];
decinv[i]:= [ [1] ];
basicset[i]:= ordblocks[i];
else
if IsBound( basicset[i] ) then
if IsBound( brauertree[i] ) and brauertree[i] <> false then
decinv[i]:= DecMat( brauertree[i]){
Filtered( [ 1 .. Length( ordblocks[i] ) ],
x -> ordblocks[i][x] in basicset[i] )
}^(-1) ;
fi;
if IsBound( decinv[i] ) then
block:= decinv[i] * restricted{ basicset[i] };
for j in [ 1 .. Length( modblocks[i] ) ] do
irreducibles[ modblocks[i][j] ]:= block[j];
od;
else
Error( "at least one of the fields <decinv>, <brauertree> must",
" be bound at pos. ", i );
fi;
else
Print( "#E BrauerTable: no basicset for block ", i, "\n" );
fi;
fi;
result.blocks[i]:= rec( defect := defect[i],
ordchars := ordblocks[i],
modchars := modblocks[i],
decinv := decinv[i],
basicset := basicset[i] );
if IsBound( brauertree[i] ) and brauertree[i] <> false then
result.blocks[i].brauertree:= brauertree[i];
fi;
od;
result.irreducibles:= irreducibles;
# decode the 'irredinfo' field
# (contains 2nd indicator if the prime is 2, else nothing)
result.irredinfo:= List( result.irreducibles, x -> rec() );
if IsBound( libtbl.indicator ) then
for i in [ 1 .. Length( result.irredinfo ) ] do
result.irredinfo[i].indicator:= [ , libtbl.indicator[i] ];
od;
fi;
#T BAD HACK until incomplete tables disappeared ...
if IsBound( libtbl.warning ) then
Print( "#W warning for table of '", libtbl.identifier, "':\n",
libtbl.warning, "\n" );
fi;
return result;
end;
#############################################################################
##
#F LibraryTables( <filename> )
##
LibraryTables := function( filename )
local file, found;
if not IsBound( LIBTABLE.LOADSTATUS.( filename ) )
or LIBTABLE.LOADSTATUS.( filename ) = "unloaded" then
# It is necessary to read a library file.
# First unload all files which are not '"userloaded"', except that
# with the ordinary resp. Brauer tables corresponding to those in
# the file 'filename'
for file in RecFields( LIBTABLE.LOADSTATUS ) do
if LIBTABLE.LOADSTATUS.( file ) <> "userloaded" and
filename{ [ 4 .. Length( filename ) ] }
<> file{ [ 4 .. Length( file ) ] } then
LIBTABLE.( file ):= rec();
LIBTABLE.LOADSTATUS.( file ):= "unloaded";
fi;
od;
# Try to read the file.
LIBTABLE.( filename ):= rec();
LIBTABLE.TABLEFILENAME:= filename;
#T allow to read files in other directories if the tables were notified there!
ALN:= Ignore;
found:= ReadPath( TBLNAME, filename, ".tbl", "ReadTbl" );
ALN:= NotifyCharTableName;
if not found then
Print( "#E ReadTbl: no file with name '", filename,
"' in the GAP table collection\n" );
return false;
fi;
# Reset the load status.
LIBTABLE.LOADSTATUS.( filename ):= "loaded";
fi;
return LIBTABLE.( filename );
end;
#############################################################################
##
#F CharTableLibrary( [ <tblname> ] )
##
## returns the library table that is known to have name <tblname>,
## if exists; otherwise 'false' is returned and a message is printed.
##
#F CharTableLibrary( [ <series>, <parameters> ] )
##
## returns the character table which is got from the generic table of the
## series with name <series> by specialising with <parameters>, if these
## parameters are admissible; otherwise 'false' is returned and a message
## is printed.
##
CharTableLibrary := function( arglist )
local i, j, tblname, firstname, filename, libtbl, fld, file,
newirredinfo, info, pos, name, fus;
if arglist = [] or not IsString( arglist[1] ) then
Error( "usage: CharTableLibrary( [ <tblname> ] )\n",
" resp. CharTableLibrary( [ <series>, <parameters> ] )" );
elif Length( arglist ) = 1 then
# 'CharTableLibrary( tblname )'
tblname:= arglist[1];
firstname:= LibInfoCharTable( tblname );
if firstname = false then
Print( "#E CharTableLibrary: no library table with name '",
tblname, "'\n" );
return false;
fi;
filename:= firstname.fileName;
firstname:= firstname.firstName;
if filename{ [ 1 .. 3 ] } = "ctb" then
# Brauer table, call 'BrauerTable'
# (First get the ordinary table.)
return BrauerTable( firstname,
CharTable( PartsBrauerTableName( firstname ).ordname ) );
fi;
# ordinary or generic table
fld:= LibraryTables( filename );
if not IsBound( fld.( firstname ) ) then
Print("#E CharTable: no library table with name '",tblname,"'\n");
return false;
fi;
libtbl := Copy( fld.( firstname ) );
libtbl.identifier := firstname;
libtbl.operations := CharTableOps;
# If the table is a generic table, simply return it.
if IsBound( libtbl.isGenericTable )
and libtbl.isGenericTable = true then
return libtbl;
fi;
# Concatenate the lines of the 'text' component.
if IsBound( libtbl.text ) and IsString( libtbl.text[1] ) then
libtbl.text:= Concatenation( libtbl.text );
fi;
# Store the fusion sources.
pos:= Position( LIBLIST.firstnames, firstname );
libtbl.fusionsource:= Copy( LIBLIST.fusionsource[ pos ] );
# Evaluate characters encoded as '[GALOIS,[i,j]]' or '[TENSOR,[i,j]]'.
if IsBound( libtbl.projectives ) then
fld:= libtbl.projectives;
libtbl.projectives:= [];
for i in [ 1, 3 .. Length( fld ) - 1 ] do
EvalChars( fld[i+1] );
for fus in LIBLIST.projections do
if fus[2] = firstname and fus[1] = fld[i] then
Add( libtbl.projectives, rec(
name := fld[i],
chars := fld[i+1],
map := fus[3]
) );
fi;
od;
od;
fi;
# Obey the construction component.
if IsBound( libtbl.construction ) then
#T changed!
# There are tables whose construction component uses {\GAP}~4
# features.
# We circumvent these traps where possible.
if ForAny( GAP_4_SPECIALS, pair -> libtbl.identifier = pair[1] ) then
First( GAP_4_SPECIALS,
pair -> libtbl.identifier = pair[1] )[2]( libtbl );
elif IsFunc( libtbl.construction ) then
libtbl.construction( libtbl );
else
ApplyFunc(
ValueGlobal( libtbl.construction[1] ),
Concatenation( [ libtbl ],
libtbl.construction{ [ 2 .. Length(
libtbl.construction ) ] } ) );
fi;
fi;
# Maybe 'construction' destroyed the 'identifier' value \ldots
#T really?
libtbl.identifier:= firstname;
libtbl.name:= firstname;
# initialize some components
if not IsBound( libtbl.size ) then
libtbl.size:= libtbl.centralizers[1];
fi;
libtbl.order:= libtbl.size;
InitClassesCharTable( libtbl );
if IsBound( libtbl.powermap ) and libtbl.powermap <> [] and
not IsBound( libtbl.orders ) then
libtbl.orders:= ElementOrdersPowermap( libtbl.powermap );
fi;
if not IsBound( libtbl.irreducibles ) then
libtbl.irreducibles:= [];
fi;
if IsBound( libtbl.automorphisms )
and IsList( libtbl.automorphisms ) then
libtbl.automorphisms:= Group( libtbl.automorphisms, () );
fi;
# Evaluate characters encoded as '[GALOIS,[i,j]]' or '[TENSOR,[i,j]]'.
EvalChars( libtbl.irreducibles );
# if necessary, decode the irredinfo field
# ('irredinfo' is then a record, its fields are lists, each element
# a list of same length as 'irreducibles')
if IsBound( libtbl.irredinfo ) then
if IsRec( libtbl.irredinfo ) then
newirredinfo:= List( libtbl.irreducibles, x -> rec() );
for fld in RecFields( libtbl.irredinfo ) do
info:= libtbl.irredinfo.( fld );
for i in [ 1 .. Length( newirredinfo ) ] do
newirredinfo[i].( fld ):= [];
od;
for i in [ 1 .. Length( info ) ] do
for j in [ 1 .. Length( newirredinfo ) ] do
if IsBound( info[i] ) then
newirredinfo[j].( fld )[i]:= info[i][j];
fi;
od;
od;
od;
libtbl.irredinfo:= newirredinfo;
fi;
else
libtbl.irredinfo:= List( libtbl.irreducibles, x -> rec() );
fi;
return libtbl;
else
if arglist[1] = "Quaternionic" and Length( arglist ) = 2
and IsInt( arglist[2] ) then
return CharTableQuaternionic( arglist[2] );
elif arglist[1] = "GL" and Length( arglist ) = 3
and IsInt( arglist[2] ) and IsInt( arglist[3] ) then
# 'CharTable( GL, 2, q )'
if arglist[2] = 2 then
return CharTableSpecialized( CharTableLibrary(["GL2"]), arglist[3] );
else
Print( "#E CharTable: table of GL(", String( arglist[2] ),
",q) not yet implemented." );
return false;
fi;
elif arglist[1] = "SL" and Length( arglist ) = 3
and IsInt( arglist[2] ) and IsInt( arglist[3] ) then
# CharTable( SL, 2, q )
if arglist[2] = 2 then
if arglist[3] mod 2 = 0 then
return CharTableSpecialized( CharTableLibrary(["SL2even"]),
arglist[3] );
else
return CharTableSpecialized( CharTableLibrary(["SL2odd"]),
arglist[3] );
fi;
else
Print( "#E CharTableLibrary: table of SL(", String( arglist[2] ),
",q) not yet implemented." );
return false;
fi;
elif arglist[1] = "PSL" and Length( arglist ) = 3
and IsInt( arglist[2] ) and IsInt( arglist[3] ) then
# CharTable( PSL, 2, q )
if arglist[2] = 2 then
if arglist[3] mod 2 = 0 then
return CharTableSpecialized( CharTableLibrary(["SL2even"]),
arglist[3] );
elif ( arglist[3] - 1 ) mod 4 = 0 then
return CharTableSpecialized( CharTableLibrary(["PSL2even"]),
arglist[3] );
else
return CharTableSpecialized( CharTableLibrary(["PSL2odd"]),
arglist[3] );
fi;
else
Print( "#E CharTableLibrary: table of PSL(", String( arglist[2] ),
",q) not yet implemented." );
return false;
fi;
elif arglist[1] = "GU" and Length( arglist ) = 3
and IsInt( arglist[2] ) and IsInt( arglist[3] ) then
# 'CharTable( GU, 3, q )'
if arglist[2] = 3 then
return CharTableSpecialized( CharTableLibrary(["GU3"]), arglist[3] );
else
Print( "#E CharTable: table of GU(", String( arglist[2] ),
",q) not yet implemented." );
return false;
fi;
elif arglist[1] = "SU" and Length( arglist ) = 3
and IsInt( arglist[2] ) and IsInt( arglist[3] ) then
# CharTable( SU, 3, q )
if arglist[2] = 3 then
return CharTableSpecialized( CharTableLibrary(["SU3"]),
arglist[3] );
else
Print( "#E CharTableLibrary: table of SU(", String( arglist[2] ),
",q) not yet implemented." );
return false;
fi;
elif arglist[1] = "Suzuki" and Length( arglist ) = 2
and IsInt( arglist[2] ) then
if not Set( FactorsInt( arglist[2] ) ) = [2] then
Print( "#E CharTable(\"Suzuki\",q): q must be a power of 2\n");
return false;
fi;
return CharTableSpecialized( CharTableLibrary(["Suzuki"]),
[arglist[2],2^((Length(FactorsInt(arglist[2]))+1)/2)] );
else
return
CharTableSpecialized( CharTableLibrary([arglist[1]]), arglist[2] );
fi;
fi;
end;
#############################################################################
##
#F OfThose()
#F IsSporadicSimple()
##
## dummy functions for selection function
##
OfThose := function( ) Error("this is just a dummy function" ); end;
IsSporadicSimple := function(G) Error("this is just a dummy function" ); end;
SchurCover := function( ) Error("this is just a dummy function" ); end;
AutomorphismGroup
:= function( ) Error( "this is just a dummy function" ); end;
#############################################################################
##
#F AllCharTableNames( ) . . . . . . all ordinary table names in the library
#F AllCharTableNames( IsSimple, true )
#F AllCharTableNames( IsSporadicSimple, true )
#F AllCharTableNames( <func>, <val> )
#F AllCharTableNames( ..., OfThose, AutomorphismGroup )
#F AllCharTableNames( ..., OfThose, SchurCover )
#F AllCharTableNames( ..., OfThose, <func> ) # e.g. <func> = CharTable ???
##
## selection function for {\GAP} library tables
##
AllCharTableNames := function( arg )
local sporsimp, list, pos, i, t, pp, oft, funcs, resul,
newlist, multinfo, autoinfo, simpinfo;
if Length( arg ) = 0 then
# all table names in the library
return Copy( LIBLIST.firstnames );
fi;
# table names of sporadic simple groups
# (sorted according to size)
sporsimp:= LIBLIST.sporadicSimple;
multinfo:= List( LIBLIST.simpleInfo, x -> x[1] );
autoinfo:= List( LIBLIST.simpleInfo, x -> x[3] );
simpinfo:= List( LIBLIST.simpleInfo, x -> x[2] );
# initialize the names list;
# supported up to now: special cases 'IsSimple', 'IsSporadicSimple'
if arg[1] = IsSimple and arg[2] = true then
list:= Copy( simpinfo );
pos:= 3;
elif arg[1] = IsSporadicSimple and arg[2] = true then
list:= sporsimp;
pos:= 3;
else
list:= LIBLIST.firstnames;
pos:= 1;
fi;
# now there are two possibilities:
# Either one filters the actual list 'list',
# or we reach an 'OfThose', so we replace each entry of 'list' by
# the list of images under the mapping instruction after 'OfThose'
while pos <= Length( arg ) do
oft:= Position( arg, OfThose, pos - 1 );
if oft = false then
oft:= Length( arg ) + 1;
fi;
# filter between two 'OfThose' mappings
funcs:= [];
resul:= [];
for i in [ pos, pos + 2 .. oft - 2 ] do
Add( funcs, arg[ i ] );
Add( resul, arg[ i+1 ] );
od;
if funcs <> [] then
newlist:= [];
for i in list do
t:= CharTable( i );
if ForAll( [ 1 .. Length( funcs ) ],
x -> funcs[x]( t ) = resul[x] ) then
Add( newlist, i );
fi;
od;
else
newlist:= list;
fi;
if Length( arg ) > oft then
# mapping instruction 'OfThose',
# supported special cases are
# 'SchurCover', 'AutomorphismGroup'.
list:= [];
if arg[ oft + 1 ] = SchurCover then
for i in newlist do
pp:= Position( simpinfo, i );
if pp = false then
Error( "no info about Schur multiplier of '", i,
"' stored" );
fi;
if multinfo[ pp ] = "" then
Add( list, simpinfo[ pp ] );
else
Add( list, Concatenation( multinfo[ pp ], ".",
simpinfo[ pp ] ) );
fi;
od;
elif arg[ oft + 1 ] = AutomorphismGroup then
for i in newlist do
pp:= Position( simpinfo, i );
if pp = false then
Error( "no info about automorphism group of '", i,
"' stored" );
fi;
if autoinfo[ pp ] = "" then
Add( list, simpinfo[ pp ] );
else
Add( list, Concatenation( simpinfo[ pp ], ".",
autoinfo[ pp ] ) );
fi;
od;
else
list:= [];
for i in newlist do
resul:= arg[ oft+1 ]( i );
if IsString( resul ) then
Add( list, resul );
elif ForAll( resul, IsString ) then
UniteSet( list, resul );
else
Error( "<arg>[", oft+1, "] must return a (list of) strings" );
fi;
od;
fi;
else
list:= newlist;
fi;
pos:= oft + 2;
od;
return list;
end;
#T change strategy: if necessary construct the character table once,
#T then trace it through the whole argument!
#############################################################################
##
#F ShrinkClifford( <tbl> )
##
## shrinks the cliffordtable in a compact form, the cliffordrecords are
## changed to library version
## in the library-chartable only cltbl.ident of the inertiagfactorgroups
## are stored. "ident" is bound in CliffordTable and should be correct.
## the user is responsible for the correctness of "ident" himself
##
ShrinkClifford := function( tbl )
local i, flds, cltbl;
cltbl:= tbl.cliffordTable;
cltbl.Ti.tables := cltbl.Ti.ident;
cltbl.cliffordrecords:= [];
for i in [1..cltbl.size] do
cltbl.cliffordrecords[i]:= ClfToCll( cltbl.(i) );
Unbind( cltbl.(i) );
od;
Unbind( tbl.irreducibles);
Unbind( cltbl.Ti.ident );
Unbind( cltbl.Ti.expN );
for flds in [ "name", "grpname", "elements", "isDomain", "operations",
"charTable", "size", "expN" ] do
Unbind( cltbl.(flds) );
od;
end;
#############################################################################
##
#F TextString( <text> )
##
## returns a string that is printed as
##
## [
## "<line_1>\n",
## "<line_1>\n",
## ...
## "<line_n>"
## ]
##
## where <line_i> is the <i>-th line of the output of 'Print( <text> )',
## except that the doublequotes are escaped.
##
## *Note* that the ']' is the last output character.
##
TextString := function( text )
local str, start, stop, line, len, pos;
str:= "[\n\"";
stop:= 1;
len:= Length( text );
while stop <= len do
start:= stop;
while stop <= len and text[stop] <> '\n' do
stop:= stop + 1;
od;
line:= text{ [ start .. stop-1 ] };
pos:= Position( line, '\"' );
while pos <> false do
line:= Concatenation( line{ [ 1 .. pos-1 ] },
"\\\"", line{ [ pos+1 .. Length( line ) ] } );
pos:= Position( line, '\"', pos + 1 );
od;
Append( str, line );
if stop <= len then
Append( str, "\\n\",\n\"" );
stop:= stop+1; # skip the '\n'
fi;
od;
Append( str, "\"\n]" );
return str;
end;
#############################################################################
##
#F BlanklessPrint( <obj> )
##
## outputs <obj> without unnecessary blanks;
##
## ('text' field and strings in a 'irreducibles' list are not treated
## in a special way!)
##
BlanklessPrint := function( obj )
local i, flds;
if TYPE( obj ) = "string" then
if '\n' in obj then
Print( TextString( obj ) );
else
Print( "\"", obj, "\"" );
fi;
elif IsList( obj ) then
Print( "[" );
for i in [ 1 .. Length( obj ) - 1 ] do
if IsBound( obj[i] ) then BlanklessPrint( obj[i] ); fi;
Print( "," );
od;
if obj <> [] then BlanklessPrint( obj[ Length( obj ) ] ); fi;
Print( "]" );
elif IsRec( obj ) then
Print( "rec(" );
flds:= RecFields( obj );
for i in [ 1 .. Length( flds ) - 1 ] do
Print( flds[i], ":=" );
BlanklessPrint( obj.( flds[i] ) );
Print( ",\n" );
od;
if Length( flds ) > 0 then
i:= Length( flds );
Print( flds[i], ":=" );
BlanklessPrint( obj.( flds[i] ) );
fi;
Print( ")" );
else
Print( obj );
fi;
end;
#############################################################################
##
#F ShrinkChars( <chars> )
##
## returns the list corresponding to the list <chars> where
##
## each '<chars>[<k>]' that is the tensor product of '<chars>[<i>]'
## and a linear character '<chars>[j]' with $i, j \leq k$ is replaced by
## the string '\"[TENSOR,[<i>,<j>]]\"', and
##
## each '<chars>[<k>]' that is the <j>-th Galois conjugate of '<chars>[<i>]'
## with $i \leq k$ is replaced by the string '\"[GALOIS,[<i>,<j>]]\"'.
##
## (used by 'PrintToLib')
##
ShrinkChars := function( chars )
local i, j, k, N, oldchars, linear, chi, fams, pos, ppos;
linear:= Filtered( chars, x -> x[1] = 1 );
fams:= GaloisMat( chars ).galoisfams;
chars:= ShallowCopy( chars );
oldchars:= ShallowCopy( chars );
if Length( linear ) > 1 then
ppos:= List( linear, x -> Position( chars, x ) );
for i in [ 1 .. Length( chars ) ] do
chi:= chars[i];
if not IsString( chi ) then
for j in [ 1 .. Length( linear ) ] do
pos:= Position( chars, Tensored( [ linear[j] ],[ chi ] )[1] );
if pos <> false and pos > i and pos > ppos[j] then
chars[ pos ]:= Concatenation( "\n[TENSOR,[",
String(i),",",String( ppos[j] ),"]]");
fi;
od;
fi;
od;
fi;
for i in [ 1 .. Length( chars ) ] do
if IsList( fams[i] ) then
for j in [ 2 .. Length( fams[i][1] ) ] do
if fams[i][1][j] <= Length( chars ) then
chi:= chars[ fams[i][1][j] ];
if not IsString( chi ) then
N:= Lcm( List( chi, NofCyc ) );
k:= First( [ 2..N ], x -> chi = List( oldchars[i],
y -> GaloisCyc(y,x) ) );
chars[ fams[i][1][j] ]:=Concatenation("\n[GALOIS,[",
String(i),",",String(k),"]]");
fi;
fi;
od;
fi;
od;
return chars;
end;
#############################################################################
##
#F ClfToCll( <clf> )
##
## returns a list encoding the information in the Clifford matrix record
## <clf>.
## <clf> must contain the components 'mat', ...
##
## See "CllToClf" for the meaning of the entries.
##
ClfToCll := function( clf )
local p, # position of the Clifford matrix clm in CLM[*]
cll, # compressed record
clm, # the pure Clifford matrix consisting of "mat" and "colw"
clmlist, # list of stored cliffordrecords
l,
lname, # name of item in the library
list, #
tr;
# Check the input.
if not IsRec( clf ) or
not IsBound( clf.inertiagrps ) or
not IsBound( clf.fusionclasses ) or
not IsBound( clf.mat ) then
Error( "<clf> must be record with components 'inertiagrps', 'mat' ",
"and 'fusionclasses'" );
fi;
l:= Length( clf.mat[1] );
cll:= [ clf.inertiagrps, clf.fusionclasses ];
if IsBound( clf.splitinfos ) then
lname := "exsp";
cll[4]:= [ clf.splitinfos.classindex, clf.splitinfos.p ];
if IsBound( clf.splitinfos.numclasses ) then
cll[4][3]:= clf.splitinfos.numclasses;
fi;
if IsBound( clf.splitinfos.root ) then
cll[4][4]:= clf.splitinfos.root;
fi;
else
lname := "elab";
fi;
if l = 2 then
# Store the full matrix.
cll[3]:= clf.mat;
elif 2 < l then
clm:= clf.mat;
cll[3]:= clm;
# Try to find the matrix in the library of Clifford matrices.
clmlist := LibraryTables( Concatenation( "clm", lname ) );
if not IsList( clmlist ) then
Error( "#E ClfToCll: can't find library of Clifford matrices.\n" );
fi;
if IsBound( clmlist[l] ) then
list:= clmlist[l];
p:= Position( list, clm );
if p <> false then
# Just store the library code.
cll[3]:= [ lname, l, p ];
return cll;
else
# The matrix itself is not in the library.
# Perhaps it is contained up to permutations of rows/columns,
# in this case print an appropriate message.
for p in [ 1 .. Length( list ) ] do
tr:= TransformingPermutations( clm, list[p] );
if tr <> false then
# The matrix can be permuted to a library matrix.
cll[3]:= [ lname, l, p ];
if tr.rows <> () then
cll[3][4]:= tr.rows^-1;
fi;
if tr.columns <> () then
cll[3][5]:= tr.columns^-1;
fi;
return cll;
fi;
od;
Print( "#I Clifford matrix not found in the library\n" );
# 'clm' not found in library, either because given libname is wrong or
# the matrix must be added first by an authorized person.
# The order would be:
# PrintClmsToLib( <file>, [clf] );
fi;
fi;
fi;
return cll;
end;
#############################################################################
##
#F PrintFusion( <name>, <fus> )
##
PrintFusion := function( name, fus )
local i, linelen;
linelen:= Length( name ) + Length( fus.name ) + 11;
Print( "ALF(\"", name, "\",\"", fus.name, "\",[" );
for i in [ 1 .. Length( fus.map ) - 1 ] do
if linelen + Length( String( fus.map[i] ) ) + 1 < 75 then
linelen:= linelen + Length( String( fus.map[i] ) ) + 1;
else
Print( "\n" );
linelen:= Length( String( fus.map[i] ) ) + 1;
fi;
Print( fus.map[i], "," );
od;
i:= Length( fus.map );
if linelen + Length( String( fus.map[i] ) ) + 1 < 75 then
linelen:= linelen + Length( String( fus.map[i] ) ) + 1;
else
Print( "\n" );
linelen:= Length( String( fus.map[i] ) ) + 1;
fi;
Print( fus.map[i], "]" );
if IsBound( fus.text ) then
Print( ",", TextString( fus.text ) );
fi;
Print( ");\n" );
end;
#############################################################################
##
#F PrintToLib( <file>, <tbl> )
##
## prints the character table <tbl> in library format to the file
## '<file>.tbl'; this is the filename relative to a directory given by
## 'TBLNAME'.
##
PrintToLib := function( file, tbl )
local func;
if not ( IsRec( tbl ) and IsBound( tbl.identifier ) ) then
Error( "usage: PrintToLib( <file>, <tbl> ) for ",
"character table record <tbl>" );
fi;
tbl:= ShallowCopy( tbl );
# if 'file' has already extension '.tbl', remove this
if Length( file ) > 3 and
file{ [ Length( file ) - 3 .. Length( file ) ] } = ".tbl" then
file:= file{ [ 1 .. Length( file ) - 4 ] };
fi;
func:= function( tbl )
local flds,
i, j,
name,
special,
chars,
fusions,
libinfo,
maxes,
fld,
info,
newirredinfo,
fus,
names,
linelen;
name:= tbl.identifier;
# header;
# check whether the file name contains special characters
if '.' in file then
file:= Concatenation( "(\"", file, "\")" );
fi;
# Check whether the representative orders are redundant.
if IsBound( tbl.powermap ) and tbl.powermap <> [] and
IsBound( tbl.orders ) and
tbl.orders = ElementOrdersPowermap( tbl.powermap ) then
Unbind( tbl.orders );
fi;
if IsBound( tbl.size ) and tbl.size = tbl.centralizers[1] then
Unbind( tbl.size );
fi;
if IsBound( tbl.fusions ) then
fusions:= tbl.fusions;
else
fusions:= [];
fi;
if IsBound( tbl.libinfo ) then
libinfo:= tbl.libinfo;
else
libinfo:= rec();
fi;
if IsBound( tbl.maxes ) then
maxes:= tbl.maxes;
else
maxes:= [];
fi;
# Remove redundant components.
for fld in [ "classes", "fusionsource", "group",
"inverse", "name", "operations", "order", "ordinary",
"projections", "projectionsource",
"fusions", "libinfo", "maxes" ] do
Unbind( tbl.( fld ) );
od;
for fld in [ "irreducibles", "irredinfo", "decinv", "decmat" ] do
if IsBound( tbl.( fld ) ) and tbl.( fld ) = [] then
Unbind( tbl.( fld ) );
fi;
od;
if IsBound( tbl.brauertree ) then
for i in [ 1 .. Length( tbl.brauertree ) ] do
if IsBound( tbl.brauertree[i] ) then
if tbl.brauertree[i] = false then
Unbind( tbl.brauertree[i] );
else
Unbind( tbl.basicset[i] );
fi;
fi;
od;
if tbl.basicset = [] then Unbind( tbl.basicset ); fi;
if tbl.brauertree = [] then Unbind( tbl.brauertree ); fi;
fi;
# shrink the irreducibles and projectives
if IsBound( tbl.irreducibles ) then
if not IsBound( tbl.construction ) then # maybe one prints a table
# that is not evaluated by
# 'CharTable' !
EvalChars( tbl.irreducibles );
fi;
if IsMat( tbl.irreducibles ) then # not list of projectives info
tbl.irreducibles:= ShrinkChars( tbl.irreducibles );
fi;
fi;
if IsBound( tbl.projectives ) then
tbl.projectives:= Copy( tbl.projectives );
for i in [ 1 .. Length( tbl.projectives ) ] do
EvalChars( tbl.projectives[i].chars );
tbl.projectives[i].chars:= ShrinkChars( tbl.projectives[i].chars );
od;
fi;
# Shrink the Clifford records.
if IsBound( tbl.cliffordTable ) then
if IsBound( tbl.irreducibles ) then
tbl.cliffordTable:= Copy( tbl.cliffordTable );
#T Shallow?
ShrinkClifford( tbl );
fi;
if IsRec( tbl.cliffordTable ) then
tbl.cliffordTable:= [ tbl.cliffordTable.Ti.fusions,
tbl.cliffordTable.Ti.tables,
tbl.cliffordTable.cliffordrecords ];
fi;
fi;
# if necessary, encode the irredinfo component
if IsBound( tbl.irredinfo ) and IsList( tbl.irredinfo ) then
newirredinfo:= rec();
for fld in RecFields( tbl.irredinfo[1] ) do
newirredinfo.( fld ):= [];
info:= tbl.irredinfo[1].( fld );
for i in [ 1 .. Length( info ) ] do
if IsBound( info[i] ) then
newirredinfo.( fld )[i]:=
List( tbl.irredinfo, x -> x.( fld )[i] );
fi;
od;
od;
tbl.irredinfo:= newirredinfo;
fi;
# Replace 'automorphisms' by the generators list.
if IsBound( tbl.automorphisms ) and IsGroup( tbl.automorphisms ) then
tbl.automorphisms:= tbl.automorphisms.generators;
fi;
if IsBound( tbl.galomorphisms ) and IsGroup( tbl.galomorphisms ) then
tbl.galomorphisms:= tbl.galomorphisms.generators;
fi;
# special cases are 'irreducibles' and 'projectives' since
# after the call of 'ShrinkChars' they may
# contain strings which shall be printed without '"'
special:= function( chars )
local j;
Print( "[" );
for j in [ 1 .. Length( chars ) - 1 ] do
if IsBound( chars[j] ) then
if IsString( chars[j] ) then
Print( chars[j] ); # strip the '"'
else
BlanklessPrint( chars[j] );
fi;
fi;
Print( "," );
od;
if chars <> [] then
j:= Length( chars );
if IsString( chars[j] ) then
Print( chars[j] ); # strip the '"'
else
BlanklessPrint( chars[j] );
fi;
fi;
Print( "]" );
end;
# Print the compulsory components.
Print( "MOT(\"", tbl.identifier, "\",\n" );
if IsBound( tbl.text ) then
Print( TextString( tbl.text ), ",\n" );
else
Print( "0,\n" );
fi;
if IsBound( tbl.centralizers ) then
BlanklessPrint( tbl.centralizers );
Print( ",\n" );
else
Print( "0,\n" );
fi;
if IsBound( tbl.powermap ) then
BlanklessPrint( tbl.powermap );
Print( ",\n" );
else
Print( "0,\n" );
fi;
if IsBound( tbl.irreducibles ) then
special( tbl.irreducibles );
Print( ",\n" );
else
Print( "0,\n" );
fi;
if IsBound( tbl.automorphisms ) then
BlanklessPrint( tbl.automorphisms );
else
Print( "0" );
fi;
if IsBound( tbl.construction ) then
#T changed!
if tbl.construction = ConstructDirectProduct then
Print( ",\nConstructDirectProduct" );
elif tbl.construction = ConstructClifford then
Print( ",\nConstructClifford" );
else
Print( ",\n", tbl.construction );
fi;
# better more careful!
fi;
Print( ");\n" );
Unbind( tbl.identifier );
Unbind( tbl.text );
Unbind( tbl.centralizers );
Unbind( tbl.powermap );
Unbind( tbl.irreducibles );
Unbind( tbl.automorphisms );
Unbind( tbl.construction );
# Print the optional components.
flds:= RecFields( tbl );
for fld in flds do
Print( "ARC(\"", name, "\",\"", fld, "\"," );
if fld = "projectives" then
chars:= tbl.projectives;
Print( "[" );
for j in chars do
Print( "\"", j.name, "\"," );
special( j.chars );
Print( "," );
od;
Print( "]" );
else
BlanklessPrint( tbl.( fld ) );
fi;
Print( ");\n" );
od;
# Write the fusion assignments to the file.
if fusions <> [] then
for fus in fusions do
PrintFusion( name, fus );
od;
fi;
# Write the names information to the file.
if libinfo <> rec() then
names:= [];
if IsBound( libinfo.othernames ) then
Append( names, libinfo.othernames );
fi;
if IsBound( libinfo.CASnames ) then
Append( names, libinfo.CASnames );
fi;
if names <> [] then
linelen:= Length( name ) + 8;
Print( "ALN(\"", name, "\",[" );
for i in [ 1 .. Length( names )-1 ] do
if linelen + Length( names[i] ) + 3 < 77 then
linelen:= linelen + Length( names[i] ) + 3;
else
Print( "\n" );
linelen:= Length( names[i] ) + 3;
fi;
Print( "\"", names[i], "\"," );
od;
if linelen + Length( names[ Length( names ) ] ) + 5 >= 77 then
Print( "\n" );
fi;
Print( "\"", names[ Length( names ) ], "\"]);\n" );
fi;
fi;
# Write the 'maxes' information to the file.
if maxes <> [] then
linelen:= Length( name ) + 16;
Print( "ARC(\"", name, "\",\"maxes\",[" );
for i in [ 1 .. Length( maxes )-1 ] do
if IsBound( maxes[i] ) then
if linelen + Length( maxes[i] ) + 3 < 77 then
linelen:= linelen + Length( maxes[i] ) + 3;
else
Print( "\n" );
linelen:= Length( maxes[i] ) + 3;
fi;
Print( "\"", maxes[i], "\"," );
else
if linelen + 1 < 77 then
linelen:= linelen + 1;
else
Print( "\n" );
linelen:= 1;
fi;
Print( "," );
fi;
od;
if linelen + Length( maxes[ Length( maxes ) ] ) + 5 >= 77 then
Print( "\n" );
fi;
Print( "\"", maxes[ Length( maxes ) ], "\"]);\n" );
fi;
end;
AppendTo( Concatenation( file, ".tbl" ), func( tbl ), "\n" );
end;
################################################################################
##
#F PrintClmsToLib( <file>, <clms> )
##
## prints the cliffordmatrices in libraryversion in a list on the file <file>
## which are not yet in the cliffordmatrix library or in this list
##
## <clms> must be a cliffordtable or a list of cliffordrecords
## if splitted, each cliffordrecord must contain "splitinfos",
##
PrintClmsToLib := function( filename, clms )
local ind, i, il, lclms, clm, size,
l, # clmname
clmlist,# list of cliffordmatrices in the library
lname, filename,# name of the file in the library
ir, # the internal record used here of the library
found; # whether the clm is already in the library
if not( IsCliffordTable( clms ) or
IsList( clms ) and ForAll( clms, x-> IsBound( x.mat ) and
IsBound( x.colw ) ) ) then
Error( "usage: PrintClmsToLib( <file>, <clms> ) for a list ",
"of cliffordrecords or a cliffordtable " );
fi;
if IsList( clms ) then lclms := Length( clms );
else lclms := clms.size;
fi;
ir := [];
for ind in [1..lclms] do
if IsList( clms ) then clm := clms[ind];
else clm := clms.(ind);
fi;
size := 0;
if IsBound( clm.mat ) then size := Length( clm.mat[1] ); fi;
if size = 0 then
Print("#I PrintClmsToLib: no <mat> and <colw>. Nothing done.\n");
elif size > 2 then
if IsBound( clm.splitinfos ) then
lname := "exsp";
else
lname := "elab";
fi;
l := Concatenation( lname, String( size ));
clmlist := LibraryTables( Concatenation( "clm", lname ) );
found := false;
if IsBound( clmlist[ size ] ) then
i := 0;
il := Length( clmlist[ size ] );
while ( not found and i < il ) do
i := i+1;
found := clmlist[ size ][i][1] = clm.mat
and clmlist[ size ][i][2] = clm.colw;
od;
fi;
if not found and IsBound( ir[size] ) then
i := 0;
il := Length( ir[size] );
while ( not found and i < il ) do
i := i+1;
found := ir[size][i][1] = clm.mat
and ir[size][i][2] = clm.colw;
od;
fi;
if not found then
if IsBound( ir[size] ) then
ir[size][Length( ir[size] )+1] :=
[clm.mat, clm.colw];
else
ir[size] := [ [clm.mat, clm.colw] ];
fi;
else
Print( "#I PrintClmsToLib: Matrix ", ind,
" already in library or in ", filename, ".\n" );
fi;
fi;
od;
PrintTo( filename, ir, "\n" );
return;
end;
#############################################################################
##
#F OrbitsResidueClass( <pq>, <set> )
##
OrbitsResidueClass := function( pq, set )
local gen,
orbs,
pnt,
orb,
i;
# If `pq' is a pair `[ <p>, <q> ]' then take a residue class mod <p>
# of order <q>.
# If `pq' is a triple `[ <p>, <q>, <k> ]' then take the orbits of the
# automorphism $\ast <k>$ modulo <p>, which is assumed to have order <q>.
if Length( pq ) = 2 then
gen:= PowerModInt( PrimitiveRootMod( pq[1] ), (pq[1]-1)/pq[2], pq[1] );
else
gen:= pq[3];
fi;
orbs:= [];
while Length( set ) <> 0 do
pnt:= set[1];
orb:= [];
for i in [ 1 .. pq[2] ] do
orb[i]:= pnt;
pnt:= ( pnt * gen ) mod pq[1];
od;
Add( orbs, orb );
SubtractSet( set, orb );
od;
return orbs;
end;
#############################################################################
##
#E