|
#############################################################################
##
#W ctadmin.gd GAP 4 package CTblLib Thomas Breuer
#W Ute Schiffer
##
## This file contains the declaration part of the data of the GAP
## character table library that is not automatically produced from the
## library files.
##
## 0. Global variables to handle the table library.
## 1. Representations of library tables
## 2. Functions used in the library files
## 3. Functions to construct library tables
## 4. Functions used as `construction' component of library tables
## 5. Selection functions for the table library
## 6. Functions to produce tables in library format
##
#############################################################################
##
## <#GAPDoc Label="organization">
## <Subsection Label="subsec:CTblLib data files">
## <Heading>Data Files of the &GAP; Character Table Library</Heading>
##
## The data files of the &GAP; Character Table Library
## reside in the <F>data</F> directory of the package &CTblLib;.
## <P/>
## The filenames start with <C>ct</C> (for <Q>character table</Q>),
## followed by either <C>o</C> (for <Q>ordinary</Q>),
## <C>b</C> (for <Q>Brauer</Q>),
## or <C>g</C> (for <Q>generic</Q>),
## then a description of the contents (up to <M>5</M> characters,
## e. g.,
## <C>alter</C> for the tables of alternating and related groups),
## and the suffix <C>.tbl</C>.
## <P/>
## The file <C>ctb</C><M>descr</M><C>.tbl</C> contains the known Brauer
## tables corresponding to the ordinary tables in the file
## <C>cto</C><M>descr</M><C>.tbl</C>.
## <P/>
## Each data file of the table library is supposed to consist of
## <Enum>
## <Item>
## comment lines, starting with a hash character <C>#</C>
## in the first column,
## </Item>
## <Item>
## an assignment to a component of <C>LIBTABLE.LOADSTATUS</C>,
## at the end of the file, and
## </Item>
## <Item>
## function calls of the form
## <List>
## <Item>
## <C>MBT( </C><M>name, data</M><C> )</C>
## (<Q>make Brauer table</Q>),
## </Item>
## <Item>
## <C>MOT( </C><M>name, data</M><C> )</C>
## (<Q>make ordinary table</Q>),
## </Item>
## <Item>
## <C>ALF( </C><M>from, to, map</M><C> )</C>,
## <C>ALF( </C><M>from, to, map, textlines</M><C> )</C>
## (<Q>add library fusion</Q>),
## </Item>
## <Item>
## <C>ALN( </C><M>name, listofnames</M><C> )</C>
## (<Q>add library name</Q>), and
## </Item>
## <Item>
## <C>ARC( </C><M>name, component, compdata</M><C> )</C>
## (<Q>add record component</Q>).
## </Item>
## </List>
## <P/>
## Here <M>name</M> must be the identifier value of the ordinary character
## table corresponding to the table to which the command refers;
## <M>data</M> must be a comma separated sequence of &GAP; objects;
## <M>from</M> and <M>to</M> must be identifier values of ordinary
## character tables,
## <M>map</M> a list of positive integers,
## <M>textlines</M> and <M>listofnames</M> lists list of strings,
## <M>component</M> a string, and
## <M>compdata</M> any &GAP; object.
## <P/>
## <C>MOT</C>, <C>ALF</C>, <C>ALN</C>, and <C>ARC</C>
## occur only in files containing ordinary character tables,
## and <C>MBT</C> occurs only in files containing Brauer tables.
## </Item>
## </Enum>
## <P/>
## Besides the above calls, the data in files containing ordinary and Brauer
## tables may contain only the following &GAP; functions.
## (Files containing generic character tables may contain calls to
## arbitrary &GAP; library functions.)
## <P/>
## <C>ACM</C>,
## <Ref Func="Concatenation" BookName="ref"/>,
## <Ref Func="E" BookName="ref"/>,
## <C>EvalChars</C>,
## <C>GALOIS</C>,
## <Ref Func="Length" BookName="ref"/>,
## <Ref Func="ShallowCopy" BookName="ref"/>,
## <C>TENSOR</C>, and
## <Ref Func="TransposedMat" BookName="ref"/>.
## <P/>
## The function <C>CTblLib.RecomputeTOC</C> in the file <F>gap4/maketbl.g</F>
## of the &CTblLib; package expects the file format described above,
## and to some extent it checks this format.
## <P/>
## The function calls may be continued over several lines of a file.
## A semicolon is assumed to be the last character in its line
## if and only if it terminates a function call.
## <P/>
## Names of character tables are strings
## (see Chapter <Ref Chap="Strings and Characters" BookName="ref"/>),
## i. e., they are enclosed in double quotes;
## <E>strings in table library files must not be split over several
## lines</E>, because otherwise the function <C>CTblLib.RecomputeTOC</C> may
## get confused.
## Additionally, no character table name is allowed to contain double
## quotes.
## <P/>
## There are three different ways how the table data can be stored in the
## file.
## <P/>
## <List>
## <Mark>Full ordinary tables</Mark>
## <Item>
## are encoded by a call to the function <C>MOT</C>,
## where the arguments correspond to the relevant attribute values;
## each fusion into another library table is added by a call to
## <C>ALF</C>, values to be stored in components of the table object
## are added with <C>ARC</C>, and admissible names are notified with
## <C>ALN</C>.
## The argument of <C>MOT</C> that encodes the irreducible characters is
## abbreviated as follows.
## For each subset of characters that differ just by multiplication with a
## linear character or by Galois conjugacy, only the first one is given by
## its values, the others are replaced by
## <C>[TENSOR,[i,j]]</C> (which means that the character is the tensor
## product of the <C>i</C>-th and the <C>j</C>-th character in the list)
## or <C>[GALOIS,[i,j]]</C> (which means that the character is obtained from
## the <C>i</C>-th character by applying <C>GaloisCyc( ., j )</C> to it).
## </Item>
## <Mark>Brauer tables</Mark>
## <Item>
## are stored relative to the corresponding ordinary
## tables; attribute values that can be computed by restricting from the
## ordinary table to <M>p</M>-regular classes are not stored,
## and instead of the irreducible characters the files contain
## (inverses of) decomposition matrices or Brauer trees for the blocks of
## nonzero defect.
## </Item>
## <Mark>Ordinary construction tables</Mark>
## <Item>
## have the attribute
## <Ref Func="ConstructionInfoCharacterTable"/> set,
## with value a list that contains the name of the construction
## function used and the arguments for a call to this function;
## the function call is performed by
## <Ref Func="CharacterTable" BookName="ref"/> when the table is constructed
## (<E>not</E> when the file containing the table is read).
## One aim of this mechanism is to store structured character tables such as
## tables of direct products and tables of central extensions of other
## tables in a compact way,
## see Chapter <Ref Chap="chap:constructions"/>.
## </Item>
## </List>
##
## </Subsection>
## <#/GAPDoc>
##
#############################################################################
##
## 0. Global variables to handle the table library.
##
BindGlobal( "CTblLib", rec(
SupportedAttributes:= [ "Identifier" ],
Test:= rec(),
Data:= rec(),
) );
#############################################################################
##
#V LIBTABLE
##
## is a record with the components
## <P/>
## <List>
## <Mark><C>LOADSTATUS</C></Mark>
## <Item>
## a record whose components are names of files in the table library,
## with value one of <C>"loaded"</C>, <C>"unloaded"</C>,
## <C>"userloaded"</C>,
## </Item>
## <Mark><C>TABLEFILENAME</C></Mark>
## <Item>
## the name of the file that is currently read
## (is set by <C>ReadTbl</C>),
## </Item>
## <Mark><C>unload</C></Mark>
## <Item>
## a Boolean, only one file with ordinary character tables plus perhaps
## the corresponding file with Brauer tables is kept in memory if the
## value is <K>true</K> (which is the default),
## </Item>
## <Mark><C>clmelab</C></Mark>
## <Item>
## the list for Clifford matrices of extensions by elementary abelian
## normal subgroups
## </Item>
## <Mark><C>clmexsp</C></Mark>
## <Item>
## the list for Clifford matrices of extensions by extraspecial normal
## subgroups
## </Item>
## </List>
## <P/>
## Additionally the filenames of loaded and userloaded files occur as
## components, with values the lists of data stored in the files.
##
DeclareGlobalVariable( "LIBTABLE" );
#############################################################################
##
## OrderCyc( <cyc> )
##
## This is needed for backward compatibility.
## A call of `OrderCyc' (with one argument) occurs in `ctgeneri.tbl',
## it cannot be replaced by `Order' because GAP 3 does not accept it.
##
DeclareSynonym( "OrderCyc", Order );
#############################################################################
##
## 1. Representations of library tables
##
## All these are in the library now, because the library accesses these.
##
#############################################################################
##
## 2. Functions used in the library files
##
#############################################################################
##
#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> )'.
##
DeclareGlobalFunction( "GALOIS" );
DeclareGlobalFunction( "TENSOR" );
DeclareGlobalFunction( "EvalChars" );
#############################################################################
##
#F ALF( <from>, <to>, <map>[, <text>, <spec>] ) . add library table fusions
##
## <ManSection>
## <Func Name="ALF" Arg="from, to, map[, text, spec]"/>
##
## <Description>
## <C>ALF</C> stores the fusion map <A>map</A> between the ordinary
## character tables with identifier strings <A>from</A> and <A>to</A>
## in the record encoding the table with identifier <A>from</A>.
## If the string <A>text</A> is given then it is added
## as <C>text</C> component of the fusion.
## If the argument <A>spec</A> is given then it is added
## as <C>specification</C> component of the fusion.
## <P/>
## <C>ALF</C> changes the global list <C>LIBLIST.fusionsource</C>.
## <P/>
## Note that the <C>ALF<C> statement should be placed in the file
## containing the data for the table with identifier <A>from</A>.
## </Description>
## </ManSection>
##
#############################################################################
##
#F ACM( <spec>, <dim>, <val> )
## adds a Clifford matrix to the library.
## <spec> is one of the strings "elab", "exsp".
## <dim> is the dimension of the Clifford matrix,
## <val> is the Clifford matrix itself.
##
#F ARC( <name>, <comp>, <val> )
## adds the record component <comp> with value <val> to the table record
## with name <name>.
##
## These functions are used in the library table files,
## so they assume that it is not necessary to read such a file before the
## data can be stored.
##
#############################################################################
##
#F NotifyNameOfCharacterTable( <firstname>, <newnames> )
##
## <#GAPDoc Label="NotifyNameOfCharacterTable">
## <ManSection>
## <Func Name="NotifyNameOfCharacterTable" Arg="firstname, newnames"/>
##
## <Description>
## notifies the strings in the list <A>newnames</A> as new admissible names
## for the library table with
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value <A>firstname</A>.
## If there is already another library table for which some of these names
## are admissible then an error is signaled.
## <P/>
## <Ref Func="NotifyNameOfCharacterTable"/> modifies the global variable
## <Ref Var="LIBLIST"/>.
## <P/>
## <Example>
## gap> CharacterTable( "private" );
## fail
## gap> NotifyNameOfCharacterTable( "A5", [ "private" ] );
## gap> a5:= CharacterTable( "private" );
## CharacterTable( "A5" )
## </Example>
## <P/>
## One can notify alternative names for character tables inside data files,
## using the function <C>ALN</C> instead of
## <Ref Func="NotifyNameOfCharacterTable"/>.
## The idea is that the additional names of tables from those files can be
## ignored which are controlled by <C>CTblLib.RecomputeTOC</C>.
## Therefore, <C>ALN</C> is set to <C>Ignore</C> before the file is read
## with <C>CTblLib.ReadTbl</C>,
## otherwise <C>ALN</C> is set to <Ref Func="NotifyNameOfCharacterTable"/>.
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "NotifyNameOfCharacterTable" );
#############################################################################
##
#F NotifyCharacterTable( <firstname>, <filename>, <othernames> )
##
## <#GAPDoc Label="NotifyCharacterTable">
## <ManSection>
## <Func Name="NotifyCharacterTable" Arg="firstname, filename, othernames"/>
##
## <Description>
## notifies a new ordinary table to the library.
## This table has
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value <A>firstname</A>,
## it is contained (in library format, see <Ref Func="PrintToLib"/>)
## in the file with name <A>filename</A> (without suffix <C>.tbl</C>),
## and the names contained in the list <A>othernames</A> are admissible
## for it.
## <P/>
## If the initial part of <A>filename</A> is one of <C>~/</C>, <C>/</C>
## or <C>./</C> then it is interpreted as an <E>absolute</E> path.
## Otherwise it is interpreted <E>relative</E> to the <F>data</F> directory
## of the &CTblLib; package.
## <P/>
## <Ref Func="NotifyCharacterTable"/> modifies the global variable
## <Ref Var="LIBLIST"/> for the current &GAP; session,
## after having checked that there is no other library table yet with an
## admissible name equal to <A>firstname</A>
## or contained in <A>othernames</A>.
## <P/>
## For example, let us change the name <C>A5</C> to <C>icos</C> wherever it
## occurs in the file <F>private.tbl</F> that was produced above,
## and then notify the <Q>new</Q> table in this file as follows.
## (The name change is needed because &GAP; knows already a table with name
## <C>A5</C> and would not accept to add another table with this name.)
## <P/>
## <Log>
## gap> NotifyCharacterTable( "icos", "private", [] );
## gap> icos:= CharacterTable( "icos" );
## CharacterTable( "icos" )
## gap> Display( icos );
## icos
##
## 2 2 2 . . .
## 3 1 . 1 . .
## 5 1 . . 1 1
##
## 1a 2a 3a 5a 5b
## 2P 1a 1a 3a 5b 5a
## 3P 1a 2a 1a 5b 5a
## 5P 1a 2a 3a 1a 1a
##
## X.1 1 1 1 1 1
## X.2 3 -1 . A *A
## X.3 3 -1 . *A A
## X.4 4 . 1 -1 -1
## X.5 5 1 -1 . .
##
## A = -E(5)-E(5)^4
## = (1-ER(5))/2 = -b5
## </Log>
## <P/>
## So the private table is treated as a library table.
## Note that the table can be accessed only if it has been notified in the
## current &GAP; session.
## For frequently used private tables, it may be reasonable to put the
## <Ref Func="NotifyCharacterTable"/> statements into your <F>gaprc</F> file
## (see <Ref Sect="The gap.ini and gaprc files" BookName="ref"/>),
## or into a file that is read via the <F>gaprc</F> file.
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "NotifyCharacterTable" );
#############################################################################
##
#F NotifyCharacterTables( <list> )
##
## <#GAPDoc Label="NotifyCharacterTables">
## <ManSection>
## <Func Name="NotifyCharacterTables" Arg="list"/>
##
## <Description>
## notifies several new ordinary tables to the library.
## The argument <A>list</A> must be a dense list in which each entry is a
## lists of the form <C>[ firstname, filename, othernames ]</C>, with the
## same meaning as the arguments of <Ref Func="NotifyCharacterTable"/>.
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "NotifyCharacterTables" );
#############################################################################
##
#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' constructs a record and stores it in the record
## `LIBTABLE.TABLEFILENAME'.
##
#############################################################################
##
#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 record `LIBTABLE.TABLEFILENAME'.
## The `NamesOfFusionSources' and `ProjectivesInfo' values are dealt with
## when the table is constructed by `CharacterTableFromLibrary'.
## Admissible names are notified by `ALN( <name>, <othernames> )'.
##
#############################################################################
##
#V GEN_Q_P
##
## for prime powers <q>, at position <q> the unique prime divisor of <q>
##
#F PrimeBase( <q> ) . . . . . . . . . . . . . . unique prime divisor of <q>
##
## If <q> is a prime power, `PrimeBase' computes the prime of which it is
## a power. For the sake of speed, the results are stored
## in the global list `GEN_Q_P'.
##
DeclareGlobalVariable( "GEN_Q_P",
"list where the prime <p> is stored at position <p>^<n>, if bound" );
DeclareGlobalFunction( "PrimeBase" );
#############################################################################
##
## 3. Functions to construct library tables
##
#############################################################################
##
#F LibInfoCharacterTable( <tblname> )
##
## <#GAPDoc Label="LibInfoCharacterTable">
## <ManSection>
## <Func Name="LibInfoCharacterTable" Arg="tblname"/>
##
## <Description>
## is a record with the components
## <P/>
## <List>
## <Mark><C>firstName</C></Mark>
## <Item>
## the <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value of the library table for which <A>tblname</A> is an admissible
## name, and
## </Item>
## <Mark><C>fileName</C></Mark>
## <Item>
## the name of the file in which the table data is stored.
## </Item>
## </List>
## <P/>
## If no such table exists in the &GAP; library then <K>fail</K>
## is returned.
## <P/>
## If <A>tblname</A> contains the substring <C>"mod"</C> then it is regarded
## as the name of a Brauer table.
## In this case the result is computed from that for the corresponding
## ordinary table and the characteristic.
## So if the ordinary table exists then the result is a record although
## the Brauer table in question need not be contained in the &GAP; library.
## <P/>
## <Example>
## gap> LibInfoCharacterTable( "S5" );
## rec( fileName := "ctoalter", firstName := "A5.2" )
## gap> LibInfoCharacterTable( "S5mod2" );
## rec( fileName := "ctbalter", firstName := "A5.2mod2" )
## gap> LibInfoCharacterTable( "J5" );
## fail
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "LibInfoCharacterTable" );
#############################################################################
##
#F LibraryTables( <filename> )
##
## is the list of data obtained on reading the file `<filename>.tbl'.
## If the initial part of <filename> is one of `~/', `/' or `./' then the
## file with this name is read; otherwise the name is interpreted relative
## to the `data' directory of the `ctbllib' package.
##
DeclareGlobalFunction( "LibraryTables" );
#############################################################################
##
## We replace the library function `CharacterTableFromLibrary' that just
## issues a warning about nonavailability of the Character Table Library.
##
if IsBoundGlobal( "CharacterTableFromLibrary" ) then
MakeReadWriteGlobal( "CharacterTableFromLibrary" );
UNBIND_GLOBAL( "CharacterTableFromLibrary" );
fi;
#############################################################################
##
#F CharacterTableFromLibrary( <tblname> )
#F CharacterTableFromLibrary( <series>, <param1>[, <param2>] )
##
## <#GAPDoc Label="CharacterTable_for_a_string">
## <ManSection>
## <Meth Name="CharacterTable" Arg="tblname[, para1[, para2]]"
## Label="for a string"/>
##
## <Description>
## If the only argument is a string <A>tblname</A> and if this is
## an admissible name (see <Ref Subsect="subsect:admissiblenames"/>)
## of a library character table then
## <Ref Meth="CharacterTable" Label="for a string"/> returns this
## library table, otherwise <K>fail</K>.
## <P/>
## If <Ref Meth="CharacterTable" Label="for a string"/> is called
## with more than one argument then the first must be a string
## <A>tblname</A> specifying a series of groups which is implemented via
## a generic character table,
## for example <C>"Symmetric"</C> for symmetric groups;
## the remaining arguments specialize the desired member of the series
## (see Section <Ref Sect="sec:generictables"/> for a list of
## available generic tables).
## If no generic table with name <A>tblname</A> is available or if the
## parameters are not admissible
## then <Ref Meth="CharacterTable" Label="for a string"/>
## returns <K>fail</K>.
## <P/>
## A call of <Ref Meth="CharacterTable" Label="for a string"/> may cause
## that some library files are read and that some table objects are
## constructed from the data stored in these files,
## so fetching a library table may take more time than one expects.
## <P/>
## Case is not significant for <A>tblname</A>.
## For example, both <C>"suzm3"</C> and <C>"SuzM3"</C> can be entered
## in order to access the character table of the third class of maximal
## subgroups of the sporadic simple Suzuki group.
## <P/>
## <Example>
## gap> s5:= CharacterTable( "A5.2" );
## CharacterTable( "A5.2" )
## gap> sym5:= CharacterTable( "Symmetric", 5 );
## CharacterTable( "Sym(5)" )
## gap> TransformingPermutationsCharacterTables( s5, sym5 );
## rec( columns := (2,3,4,7,5), group := Group(()),
## rows := (1,7,3,4,6,5,2) )
## </Example>
## <P/>
## The above two tables are tables of the symmetric group on five letters;
## the first is in &ATLAS; format
## (see Section <Ref Sect="sec:ATLAS Tables"/>),
## the second is constructed from the generic table for symmetric groups
## (see <Ref Sect="sec:generictables"/>).
## <P/>
## <Example>
## gap> CharacterTable( "J5" );
## fail
## gap> CharacterTable( "A5" ) mod 2;
## BrauerTable( "A5", 2 )
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "CharacterTableFromLibrary" );
#############################################################################
##
#O BrauerTable( <tblname>, <p> )
##
## <#GAPDoc Label="BrauerTable_for_a_string">
## <ManSection>
## <Oper Name="BrauerTable" Arg="tblname, p"
## Label="for a string, and a prime integer"/>
##
## <Description>
## Called with a string <A>tblname</A> and a prime integer <A>p</A>,
## <Ref Oper="BrauerTable" Label="for a string, and a prime integer"/>
## returns the <A>p</A>-modular character table of
## the ordinary character table with admissible name <A>tblname</A>,
## if such an ordinary character table exists and if &GAP; can compute its
## <A>p</A>-modular table.
## Otherwise <K>fail</K> is returned.
## <P/>
## The default method delegates to <Ref Oper="BrauerTable" BookName="ref"
## Label="for a character table, and a prime integer"/>
## with arguments the <Ref Attr="CharacterTable" Label="for a string"/>
## value of <A>tblname</A> and <A>p</A>.
## <P/>
## <Example>
## gap> BrauerTable( "A5", 2 );
## BrauerTable( "A5", 2 )
## gap> BrauerTable( "J5", 2 ); # no ordinary table with name J5
## fail
## gap> BrauerTable( "M", 2 ); # Brauer table not known
## fail
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareOperation( "BrauerTable", [ IsString, IsInt ] );
#############################################################################
##
#F PartsBrauerTableName( <modname> )
##
## is a record with components
## `ordname'
## substring up to the occurrence of `mod' in <modname>,
## `prime'
## the integer of the string after `mod'.
##
DeclareGlobalFunction( "PartsBrauerTableName" );
#############################################################################
##
#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' components of blocks in Brauer tables.
##
DeclareGlobalFunction( "BasicSetBrauerTree" );
#############################################################################
##
#F DecMatBrauerTree( <brauertree> )
##
## In the GAP table library, a Brauer tree <brauertree> is a list 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).
##
## `DecMatBrauerTree' returns the decomposition matrix of the block with
## given Brauer tree.
##
DeclareGlobalFunction( "DecMatBrauerTree" );
#############################################################################
##
#F BrauerTree( <decmat> )
##
## returns the Brauer tree of the decomposition matrix <decmat>, if exists,
## and `fail' otherwise.
##
DeclareGlobalFunction( "BrauerTree" );
#############################################################################
##
#F BrauerTableFromLibrary( <ordtbl>, <p> )
##
## is the <p>-modular Brauer table of the ordinary library table <ordtbl>.
##
DeclareGlobalFunction( "BrauerTableFromLibrary" );
#############################################################################
##
#F CharacterTableSpecialized( <generic_table>, <q> ) . . . . specialise <q>
##
## <#GAPDoc Label="CharacterTableSpecialized">
## <ManSection>
## <Func Name="CharacterTableSpecialized" Arg="gentbl, q"/>
##
## <Description>
## For a record <A>gentbl</A> representing a generic character table,
## and a parameter value <A>q</A>,
## <Ref Func="CharacterTableSpecialized"/> returns a character table object
## computed by evaluating <A>gentbl</A> at <A>q</A>.
## <P/>
## <Example>
## gap> c5:= CharacterTableSpecialized( CharacterTable( "Cyclic" ), 5 );
## CharacterTable( "C5" )
## gap> Display( c5 );
## C5
##
## 5 1 1 1 1 1
##
## 1a 5a 5b 5c 5d
## 5P 1a 1a 1a 1a 1a
##
## X.1 1 1 1 1 1
## X.2 1 A B /B /A
## X.3 1 B /A A /B
## X.4 1 /B A /A B
## X.5 1 /A /B B A
##
## A = E(5)
## B = E(5)^2
## </Example>
## <P/>
## (Also <C>CharacterTable( "Cyclic", 5 )</C> could have been used
## to construct the above table.)
## <P/>
## <Example>
## gap> HasClassParameters( c5 ); HasCharacterParameters( c5 );
## true
## true
## gap> ClassParameters( c5 ); CharacterParameters( c5 );
## [ [ 1, 0 ], [ 1, 1 ], [ 1, 2 ], [ 1, 3 ], [ 1, 4 ] ]
## [ [ 1, 0 ], [ 1, 1 ], [ 1, 2 ], [ 1, 3 ], [ 1, 4 ] ]
## gap> ClassParameters( CharacterTable( "Symmetric", 3 ) );
## [ [ 1, [ 1, 1, 1 ] ], [ 1, [ 2, 1 ] ], [ 1, [ 3 ] ] ]
## </Example>
## <P/>
## Here are examples for the <Q>local evaluation</Q> of
## generic character tables,
## first a character value of the cyclic group shown above,
## then a character value and a representative order of a symmetric group.
## <P/>
## <Example>
## gap> CharacterTable( "Cyclic" ).irreducibles[1][1]( 5, 2, 3 );
## E(5)
## gap> tbl:= CharacterTable( "Symmetric" );;
## gap> tbl.irreducibles[1][1]( 5, [ 3, 2 ], [ 2, 2, 1 ] );
## 1
## gap> tbl.orders[1]( 5, [ 2, 1, 1, 1 ] );
## 2
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "CharacterTableSpecialized" );
#############################################################################
##
## 4. Functions used as `construction' component of library tables
##
## Note that in all construction functions, the table under construction is
## a plain record, *not* a table object.
##
#############################################################################
##
#F TransferComponentsToLibraryTableRecord( <t>, <tbl> )
##
## <t> must be a library character table, and <tbl> a record that will be
## converted to a library character table later.
## `TransferComponentsToLibraryTableRecord' transfers all those values
## from <t> to <tbl> that are described by `SupportedOrdinaryTableInfo'
## and `SupportedLibraryTableComponents'.
##
DeclareGlobalFunction( "TransferComponentsToLibraryTableRecord" );
#############################################################################
##
#F InducedLibraryCharacters( <subtbl>, <tblrec>, <chars>, <fusionmap> )
##
## is the list of class function values lists
##
DeclareGlobalFunction( "InducedLibraryCharacters" );
#############################################################################
##
#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'.
##
DeclareGlobalFunction( "UnpackedCll" );
#############################################################################
##
#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
##
DeclareGlobalFunction( "CllToClf" );
#############################################################################
##
## 5. Selection functions for the table library
##
#############################################################################
##
#F CompleteGroup()
##
## dummy function for selection function
##
DeclareGlobalFunction( "CompleteGroup" );
#############################################################################
##
#F OfThose()
##
## dummy function for selection function
##
DeclareGlobalFunction( "OfThose" );
#############################################################################
##
#P IsAtlasCharacterTable( <tbl> )
##
## <#GAPDoc Label="IsAtlasCharacterTable">
## <ManSection>
## <Prop Name="IsAtlasCharacterTable" Arg="tbl"/>
##
## <Description>
## For an ordinary character table <A>tbl</A>, this function returns
## <K>true</K> if and only if the <Ref Meth="InfoText"/> value of <A>tbl</A>
## contains the string <C>"origin: ATLAS of finite groups"</C>.
## <P/>
## For a Brauer character table <A>tbl</A>, this function returns
## <K>true</K> if and only if <Ref Prop="IsAtlasCharacterTable"/>
## returns <K>true</K> for the underlying ordinary table of <A>tbl</A>.
## <P/>
## One application of this function is to restrict the search with
## <Ref Func="AllCharacterTableNames"/> to character tables from the
## &ATLAS; of Finite Groups.
## <P/>
## <Example>
## gap> Maxes( CharacterTable( "A6" ) );
## [ "A5", "A6M2", "3^2:4", "s4", "A6M5" ]
## gap> IsAtlasCharacterTable( CharacterTable( "A5" ) );
## true
## gap> IsAtlasCharacterTable( CharacterTable( "A5" ) mod 2 );
## true
## gap> IsAtlasCharacterTable( CharacterTable( "A6M2" ) );
## false
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
## Note that we do not call `DeclareAttributeSuppCT' because a `true' value
## shall not be inherited via `ConstructPermuted':
## If an Atlas table has been loaded and has been asked for its value then
## `true' is stored in it, and `ConstructPermuted' would set `true' also in
## duplicate tables.
##
DeclareProperty( "IsAtlasCharacterTable", IsCharacterTable );
#############################################################################
##
#F AllCharacterTableNames( [<func>, <val>, ...[, OfThose, <func>]]
#F [: OrderedBy:= <func>] )
##
## <#GAPDoc Label="AllCharacterTableNames">
## <ManSection>
## <Func Name="AllCharacterTableNames"
## Arg="[func, val, ...[, OfThose, func]]: OrderedBy:= func"/>
##
## <Description>
## Similar to group libraries
## (see Chapter <Ref Chap="Group Libraries" BookName="ref"/>),
## the &GAP; Character Table Library can be used to search for ordinary
## character tables with prescribed properties.
## <P/>
## A specific library table can be selected by an admissible name,
## see <Ref Subsect="subsect:admissiblenames"/>.
## <P/>
## <Index>selection function!for character tables</Index>
## The <E>selection function</E>
## (see <Ref Sect="Selection Functions" BookName="ref"/>)
## for character tables from the &GAP; Character Table Library that have
## certain abstract properties is <Ref Func="AllCharacterTableNames"/>.
## Contrary to the situation in the case of group libraries,
## the selection function returns a list not of library character tables
## but of their names;
## using <Ref Meth="CharacterTable" Label="for a string"/>
## one can then access the tables themselves.
## <P/>
## <Ref Func="AllCharacterTableNames"/> takes an arbitrary even number
## of arguments.
## The argument at each odd position must be a function, and
## the argument at the subsequent even position must be either a value
## that this function must return when called for the character table
## in question, in order to have the name of the table included in the
## selection, or a list of such values,
## or a function that returns <K>true</K> for such a value,
## and <K>false</K> otherwise.
## For example,
## <P/>
## <Example>
## gap> names:= AllCharacterTableNames();;
## </Example>
## <P/>
## returns a list containing one admissible name of each ordinary character
## table in the &GAP; library,
## <P/>
## <Example>
## gap> simpnames:= AllCharacterTableNames( IsSimple, true,
## > IsAbelian, false );;
## </Example>
## <P/>
## returns a list containing an admissible name of each ordinary character
## table in the &GAP; library whose groups are nonabelian and simple, and
## <P/>
## <Example>
## gap> AllCharacterTableNames( IsSimple, true, IsAbelian, false,
## > Size, [ 1 .. 100 ] );
## [ "A5", "A6M2", "Alt(5)" ]
## </Example>
## <P/>
## returns a list containing an admissible name of each ordinary character
## table in the &GAP; library whose groups are nonabelian and simple and
## have order at most <M>100</M>,
## respectively.
## (Note that <C>"A5"</C>, <C>"A6M2"</C>, and <C>"Alt(5)"</C>
## are identifiers of permutation equivalent character tables.
## It would be possible to exclude duplicates,
## see Section <Ref Sect="sec:duplicates"/>).
## <P/>
## Similarly,
## <P/>
## <Example>
## gap> AllCharacterTableNames( Size, IsPrimeInt );
## [ "2.Alt(2)", "Alt(3)", "C2", "C3", "Sym(2)" ]
## </Example>
## <P/>
## returns the list of all identifiers of library tables whose
## <Ref Attr="Size" BookName="ref"/> value is a prime integer, and
## <P/>
## <Example><![CDATA[
## gap> AllCharacterTableNames( Identifier,
## > x -> PositionSublist( x, "L8" ) <> fail );
## [ "L8(2)", "P1L82", "P2L82" ]
## ]]></Example>
## <P/>
## returns the identifiers that contain the string <C>"L8"</C> as a
## substring.
## <P/>
## For the sake of efficiency, the attributes whose names are listed in
## <C>CTblLib.SupportedAttributes</C> are handled in a special way,
## &GAP; need not read all files of the table library in these cases
## in order to find the desired names.
## <P/>
## <Example>
## gap> CTblLib.SupportedAttributes;
## [ "AbelianInvariants", "HasFusionToTom", "Identifier",
## "IdentifiersOfDuplicateTables", "InfoText", "IsAbelian",
## "IsAlmostSimple", "IsAtlasCharacterTable", "IsDuplicateTable",
## "IsNontrivialDirectProduct", "IsPerfect", "IsQuasisimple",
## "IsSimple", "IsSporadicSimple", "KnowsDeligneLusztigNames",
## "KnowsSomeGroupInfo", "Maxes", "NamesOfFusionSources",
## "NrConjugacyClasses", "Size" ]
## </Example>
## <P/>
## If the <Package>Browse</Package> package (see <Cite Key="Browse"/>)
## is not loaded then <C>CTblLib.SupportedAttributes</C> contains only
## <C>"Identifier"</C>, and
## <Ref Func="AllCharacterTableNames"/> will be very slow when one selects
## character tables according to other attributes from the list shown above.
## <P/>
## The global option <C>OrderedBy</C> can be used to prescribe the ordering
## of the result.
## The value of this option, if given, must be a function that takes a
## character table as its unique argument; the result list is then
## sorted according to the results of this function (w. r. t. the
## comparison by &GAP;'s <C>\<</C> operation).
## <P/>
## For example, we may be interested in the tables of small sporadic simple
## groups, ordered alphabetically or by size
## (<Ref Attr="Size" BookName="ref" Label="for a character table"/>)
## or by the number of conjugacy classes
## (<Ref Attr="NrConjugacyClasses" BookName="ref"
## Label="for a character table"/>).
## <P/>
## <Example>
## gap> AllCharacterTableNames( IsSporadicSimple, true,
## > Size, [ 1 .. 10^6 ],
## > IsDuplicateTable, false );
## [ "J1", "J2", "M11", "M12", "M22" ]
## gap> AllCharacterTableNames( IsSporadicSimple, true,
## > Size, [ 1 .. 10^6 ],
## > IsDuplicateTable, false : OrderedBy:= Size );
## [ "M11", "M12", "J1", "M22", "J2" ]
## gap> AllCharacterTableNames( IsSporadicSimple, true,
## > Size, [ 1 .. 10^6 ],
## > IsDuplicateTable, false : OrderedBy:= NrConjugacyClasses );
## [ "M11", "M22", "J1", "M12", "J2" ]
## </Example>
## <P/>
## (Note that the alphabtical ordering could also be achieved by entering
## <C>OrderedBy:= Identifier</C>.)
## <P/>
## If the dummy function <C>OfThose</C> is an argument at an odd position
## then the following argument <A>func</A> must be a function that takes a
## character table and returns a name of a character table or a list of
## names;
## this is interpreted as replacement of the names computed up to this
## position by the union of names returned by <A>func</A>.
## For example, <A>func</A> may be <Ref Attr="Maxes"/> or
## <Ref Attr="NamesOfFusionSources" BookName="ref"/>).
## <P/>
## <Example>
## gap> maxesnames:= AllCharacterTableNames( IsSporadicSimple, true,
## > HasMaxes, true,
## > OfThose, Maxes );;
## </Example>
## <P/>
## returns the union of names of ordinary tables of those maximal subgroups
## of sporadic simple groups that are contained in the table library in the
## sense that the attribute <Ref Attr="Maxes"/> is set.
## <P/>
## For the sake of efficiency, <C>OfThose</C> followed by one of the
## arguments <Ref Attr="AutomorphismGroup" BookName="ref"/>,
## <Ref Func="SchurCover" BookName="ref"/>,
## <C>CompleteGroup</C> is handled in a special way.
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "AllCharacterTableNames" );
#############################################################################
##
#F OneCharacterTableName( [<func>, <val>, ...{, OfThose, <func>}]
#F [: OrderedBy:= <func>] )
##
## <#GAPDoc Label="OneCharacterTableName">
## <ManSection>
## <Func Name="OneCharacterTableName"
## Arg="[func, val, ...[, OfThose, func]]: OrderedBy:= func"/>
##
## <Description>
## The example function for character tables from the &GAP; Character
## Table Library that have certain abstract properties is
## <Ref Func="OneCharacterTableName"/>.
## It is analogous to the selection function
## <Ref Func="AllCharacterTableNames"/>,
## the difference is that it returns one
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value of a character table with the properties in question
## instead of the list of all such values.
## If no table with the required properties is contained in the &GAP;
## Character Table Library then <K>fail</K> is returned.
## <P/>
## <Example>
## gap> OneCharacterTableName( IsSimple, true, Size, 60 );
## "A5"
## gap> OneCharacterTableName( IsSimple, true, Size, 20 );
## fail
## </Example>
## <P/>
## The global option <C>OrderedBy</C> can be used to search for a
## <Q>smallest</Q> example, according to the value of the option.
## If this function is one of the attributes
## whose names are listed in <C>CTblLib.SupportedAttributes</C> then the
## tables are processed according to increasing values of the option,
## which may speed up the search.
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "OneCharacterTableName" );
#############################################################################
##
#F NameOfEquivalentLibraryCharacterTable( <ordtbl> )
#F NamesOfEquivalentLibraryCharacterTables( <ordtbl> )
##
## <#GAPDoc Label="NameOfEquivalentLibraryCharacterTable">
## <ManSection>
## <Func Name="NameOfEquivalentLibraryCharacterTable" Arg='ordtbl'/>
## <Func Name="NamesOfEquivalentLibraryCharacterTables" Arg='ordtbl'/>
##
## <Description>
## Let <A>ordtbl</A> be an ordinary character table.
## <Ref Func="NameOfEquivalentLibraryCharacterTable"/> returns
## the <Ref Func="Identifier" Label="for character tables" BookName="ref"/>
## value of a character table in the &GAP; Character Table Library that is
## permutation equivalent to <A>ordtbl</A>
## (see <Ref Func="TransformingPermutationsCharacterTables"
## BookName="ref"/>) if such a character table exists,
## and <K>fail</K> otherwise.
## <Ref Func="NamesOfEquivalentLibraryCharacterTables"/> returns the list of
## all <Ref Func="Identifier" Label="for character tables" BookName="ref"/>
## values of character tables in the &GAP; Character Table Library that are
## permutation equivalent to <A>ordtbl</A>; thus an empty list is returned
## in this case if no equivalent library table exists.
## <P/>
## <Example>
## gap> tbl:= CharacterTable( "Alternating", 5 );;
## gap> NameOfEquivalentLibraryCharacterTable( tbl );
## "A5"
## gap> NamesOfEquivalentLibraryCharacterTables( tbl );
## [ "A5", "A6M2", "Alt(5)" ]
## gap> tbl:= CharacterTable( "Cyclic", 17 );;
## gap> NameOfEquivalentLibraryCharacterTable( tbl );
## fail
## gap> NamesOfEquivalentLibraryCharacterTables( tbl );
## [ ]
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "NameOfEquivalentLibraryCharacterTable" );
DeclareGlobalFunction( "NamesOfEquivalentLibraryCharacterTables" );
#############################################################################
##
#F UserPreference( "CTblLib", "UnloadCTblLibFiles" )
##
## <#GAPDoc Label="UnloadCTblLibFiles">
## <Subsection Label="subsect:unloadfiles">
## <Heading>Unloading Character Table Data</Heading>
##
## <Index Subkey="UnloadCTblLibFiles">user preferences</Index>
## Data files from the &GAP; Character Table Library may be read only once
## during a &GAP; session
## –this is efficient but requires memory–
## or the cached data may be erased as soon as a second data file is to be
## read –this requires less memory but is usually less efficient.
## <P/>
## One can choose between these two possibilities via the user preference
## <C>"UnloadCTblLibFiles"</C> of the <Package>CTblLib</Package> package,
## see <Ref Func="UserPreference" BookName="ref"/>.
## The default value of this preference is <K>true</K>,
## that is, the contents of only one data file is kept in memory.
## Call <C>SetUserPreference( "CTblLib", "UnloadCTblLibFiles", false );</C>
## if you want to change this behaviour.
## </Subsection>
## <#/GAPDoc>
##
DeclareUserPreference( rec( name:= "UnloadCTblLibFiles",
description:= [ "This preference controls the data files from the \
GAP Character Table Library. \
Only one such file is kept in memory if the value is 'true' (the default), \
whereas all such files are kept if the value is 'false'." ],
default:= true,
values:= [ true, false ],
multi:= false ) );
#############################################################################
##
#F UserPreference( "AtlasRep", "DisplayFunction" )
##
## <#GAPDoc Label="DisplayFunction">
## <Subsection Label="subsect:displayfunction">
## <Heading>Changing the display format of several functions</Heading>
##
## <Index Subkey="DisplayFunction">user preferences</Index>
## The way how the functions
## <Ref Func="DisplayAtlasContents"/>,
## <Ref Func="DisplayAtlasInfo" BookName="atlasrep"/>,
## <Ref Func="DisplayAtlasMap" Label="for the name of a simple group"/>,
## <!-- <Ref Func="DisplayBlockInvariants" BookName="ctblocks"/>, -->
## and <Ref Func="DisplayCTblLibInfo" Label="for a character table"/>
## show tabular information can be customized via the user preference
## <C>"DisplayFunction"</C> of the <Package>AtlasRep</Package> package,
## see Section
## <Ref Subsect="User preference DisplayFunction" BookName="AtlasRep"/>.
## </Subsection>
## <#/GAPDoc>
##
#############################################################################
##
#T UserPreference( "CTblLib", "DataDirectory" )
##
## This will become interesting as soon as remote files will be supported.
##
#############################################################################
##
#F CTblLib.ShowOnlyASCII()
##
## Show nicer grids and symbols such as ℤ if the terminal admits this.
## Currently we do not do this if `Print' is used to show the data,
## because of the automatically inserted line breaks.
##
CTblLib.ShowOnlyASCII:= function()
return UserPreference( "AtlasRep", "DisplayFunction" ) = "Print" or
GAPInfo.TermEncoding <> "UTF-8";
end;
#############################################################################
##
#F UnloadCharacterTableData()
##
## `UnloadCharacterTableData' clears the cache of character tables.
## This can be used to free up to more than hundred megabytes of space
## in the current GAP session.
##
DeclareGlobalFunction( "UnloadCharacterTableData" );
#############################################################################
##
## 6. Functions to produce tables in library format
##
#############################################################################
##
#F ShrinkClifford( <tbl> )
##
## shrinks the `cliffordTable' component.
## The Clifford records are changed to library format using `ClfToCll'.
## In the library format, only the component `ident' of the inertia factor
## groups are stored.
##
DeclareGlobalFunction( "ShrinkClifford" );
#############################################################################
##
#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.
##
DeclareGlobalFunction( "TextString" );
#############################################################################
##
#F BlanklessPrintTo( <stream>, <obj> )
##
## appends <obj> to the output stream <stream>,
## thereby trying to avoid unnecessary blanks.
## For the subobjects of <obj>, the function `PrintTo' is used.
## (So the subobjects are appended only if <stream> is of the appropriate
## type, see~"PrintTo".)
##
## If <obj> is a record then the component `text' and strings in an `irr'
## list are *not* treated in a special way!
##
## This function is used by the libraries of character tables and of tables
## of marks.
##
DeclareGlobalFunction( "BlanklessPrintTo" );
#T better use WriteAll?
#############################################################################
##
#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>]]\"'.
##
## This function is used by `PrintToLib'.
##
DeclareGlobalFunction( "ShrinkChars" );
#############################################################################
##
#F ClfToCll( <clf> )
##
## is a list encoding the information in the Clifford matrix record <clf>.
## <clf> must contain the components `mat', `inertiagrps', `fusionclasses'.
##
## See `CllToClf' for the meaning of the entries.
##
DeclareGlobalFunction( "ClfToCll" );
#T up to now no function is installed
#############################################################################
##
#F LibraryFusion( <name>, <fus> )
##
## <#GAPDoc Label="LibraryFusion">
## <ManSection>
## <Func Name="LibraryFusion" Arg="name, fus"/>
##
## <Description>
## For a string <A>name</A> that is an
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value of an ordinary character table in the &GAP; library,
## and a record <A>fus</A> with the components
## <List>
## <Mark><C>name</C></Mark>
## <Item>
## the identifier of the destination table, or this table itself,
## </Item>
## <Mark><C>map</C></Mark>
## <Item>
## the fusion map, a list of image positions,
## </Item>
## <Mark><C>text</C> (optional)</Mark>
## <Item>
## a string describing properties of the fusion, and
## </Item>
## <Mark><C>specification</C> (optional)</Mark>
## <Item>
## a string or an integer,
## </Item>
## </List>
## <Ref Func="LibraryFusion"/> returns a string whose printed value can be
## used to add the fusion in question to the library file containing
## the data for the table with identifier <A>name</A>.
## <P/>
## If <A>name</A> is a character table then its
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value is used as the corresponding string.
## <Example>
## gap> s5:= CharacterTable( "S5" );
## CharacterTable( "A5.2" )
## gap> fus:= PossibleClassFusions( a5, s5 );
## [ [ 1, 2, 3, 4, 4 ] ]
## gap> fusion:= rec( name:= s5, map:= fus[1], text:= "unique" );;
## gap> Print( LibraryFusion( "A5", fusion ) );
## ALF("A5","A5.2",[1,2,3,4,4],[
## "unique"
## ]);
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "LibraryFusion" );
#############################################################################
##
#F LibraryFusionTblToTom( <name>, <fus> )
##
## <#GAPDoc Label="LibraryFusionTblToTom">
## <ManSection>
## <Func Name="LibraryFusionTblToTom" Arg="name, fus"/>
##
## <Description>
## For a string <A>name</A> that is an
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value of an ordinary character table in the &GAP; library,
## and a record <A>fus</A> with the components
## <List>
## <Mark><C>name</C></Mark>
## <Item>
## the identifier of the destination table of marks, or this table itself,
## </Item>
## <Mark><C>map</C></Mark>
## <Item>
## the fusion map, a list of image positions,
## </Item>
## <Mark><C>text</C> (optional)</Mark>
## <Item>
## a string describing properties of the fusion, and
## </Item>
## <Mark><C>perm</C> (optional)</Mark>
## <Item>
## a permutation,
## </Item>
## </List>
## <Ref Func="LibraryFusionTblToTom"/> returns a string whose printed value
## can be used to add the fusion in question to the library file containing
## the data for the table with identifier <A>name</A>.
## <P/>
## The meaning of the component <C>perm</C> is as follows.
## Let <A>prim</A> be the primitive permutation characters obtained by
## computing the <Ref Func="PermCharsTom" BookName="ref"/> value of the
## tables of marks,
## taking the sublist at the positions in the first component of the
## <Ref Func="MaximalSubgroupsTom" BookName="ref"/> value of the tables of
## marks, and restricting these lists via the <C>map</C> component.
## Permuting <A>prim</A> with the <C>perm</C> component via
## <Ref Func="Permuted" BookName="ref"/> yields the list of
## permutation characters obtained by inducing the trivial characters of the
## subgroups given by the <Ref Attr="Maxes"/> value of the character table.
## If the component <C>perm</C> is not present and if the character table
## has the attribute <Ref Attr="Maxes"/> set then the two ways of computing
## the primitive permutation characters yield the same list.
## <P/>
## If <A>name</A> is a character table then its
## <Ref Attr="Identifier" Label="for character tables" BookName="ref"/>
## value is used as the corresponding string.
## <Example>
## gap> tbl:= CharacterTable( "A5" );
## CharacterTable( "A5" )
## gap> tom:= TableOfMarks( "A5" );
## TableOfMarks( "A5" )
## gap> fus:= PossibleFusionsCharTableTom( tbl, tom );
## [ [ 1, 2, 3, 5, 5 ] ]
## gap> fusion:= rec( name:= tom, map:= fus[1], text:= "unique" );;
## gap> Print( LibraryFusionTblToTom( "A5", fusion ) );
## ARC("A5","tomfusion",rec(name:="A5",map:=[1,2,3,5,5],text:=[
## "unique"
## ]));
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "LibraryFusionTblToTom" );
#############################################################################
##
#F PrintToLib( <file>, <tbl> )
##
## <#GAPDoc Label="PrintToLib">
## <ManSection>
## <Func Name="PrintToLib" Arg="file, tbl"/>
##
## <Description>
## prints the (ordinary or Brauer) character table <A>tbl</A>
## in library format to the file <A>file</A><C>.tbl</C>
## (or to <A>file</A> if this has already the suffix <C>.tbl</C>).
## <P/>
## If <A>tbl</A> is an ordinary table then the value of the attribute
## <Ref Attr="NamesOfFusionSources" BookName="ref"/> is ignored by
## <Ref Func="PrintToLib"/>,
## since for library tables this information is extracted from the source
## files (see Section <Ref Subsect="subsec:CTblLib data files"/>).
## <P/>
## The names of data files in the &GAP; Character Table Library begin with
## <C>cto</C> (for ordinary tables) or
## <C>ctb</C> (for corresponding Brauer tables),
## see Section <Ref Sect="sec:technicalities"/>.
## This is supported also for private extensions of the library,
## that is, if the filenames are chosen this way and the ordinary tables
## in the <C>cto</C> files are notified via
## <Ref Func="NotifyCharacterTable"/> then the Brauer tables will be found
## in the <C>ctb</C> files.
## Alternatively, if the filenames of the files with the ordinary tables do
## not start with <C>cto</C> then &GAP; expects the corresponding Brauer
## tables in the same file as the ordinary tables.
## <P/>
## <Log>
## gap> PrintToLib( "private", a5 );
## </Log>
## <P/>
## The above command appends the data of the table <C>a5</C> to the file
## <F>private.tbl</F>;
## the first lines printed to this file are
## <P/>
## <Listing>
## MOT("A5",
## [
## "origin: ATLAS of finite groups, tests: 1.o.r., pow[2,3,5]"
## ],
## [60,4,3,5,5],
## [,[1,1,3,5,4],[1,2,1,5,4],,[1,2,3,1,1]],
## [[1,1,1,1,1],[3,-1,0,-E(5)-E(5)^4,-E(5)^2-E(5)^3],
## [GALOIS,[2,2]],[4,0,1,-1,-1],[5,1,-1,0,0]],
## [(4,5)]);
## ARC("A5","projectives",["2.A5",[[2,0,-1,E(5)+E(5)^4,E(5)^2+E(5)^3],
## [GALOIS,[1,2]],[4,0,1,-1,-1],[6,0,0,1,1]],]);
## ARC("A5","extInfo",["2","2"]);
## </Listing>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareGlobalFunction( "PrintToLib" );
#############################################################################
##
#F PrintClmsToLib( <file>, <clms> )
##
## prints the Clifford matrices in library format in a list on the file
## <file> which are not yet in the Clifford matrix library or in this list.
##
## <clms> must be a Clifford table or a list of Clifford records.
## In case of splitting, each Clifford record must contain `splitinfos'.
##
DeclareGlobalFunction( "PrintClmsToLib" );
#T up to now no function is installed
#############################################################################
##
#F OrbitsResidueClass( <pq>, <set> )
##
## is used in the generic character table of the groups $p \colon q$.
## <pq> must be a list of length $2$ or $3$, the first entry being $p$,
## the second being $q$, and the third (if bound) being the residue $k$
## (modulo $p$) that forms orbits of length $q$ each on the nonzero
## residues modulo $p$.
## <set> is the set of points to act on.
##
DeclareGlobalFunction( "OrbitsResidueClass" );
#############################################################################
##
#A CASInfo( <tbl> )
##
## <#GAPDoc Label="CASInfo">
## <ManSection>
## <Attr Name="CASInfo" Arg="tbl"/>
##
## <Description>
## Let <A>tbl</A> be an ordinary character table in the &GAP; library
## that was (up to permutations of classes and characters) contained already
## in the &CAS; table library.
## When one fetches <A>tbl</A> from the library,
## one does in general not get the original &CAS; table.
## Namely, in many cases (mostly &ATLAS; tables,
## see Section <Ref Sect="sec:ATLAS Tables"/>),
## the identifier of the table (see <Ref Attr="Identifier"
## Label="for character tables" BookName="ref"/>)
## as well as the ordering of classes and
## characters are different for the &CAS; table and its &GAP; version.
## <P/>
## Note that in several cases, the &CAS; library contains
## different tables of the same group,
## in particular these tables may have different names and orderings of
## classes and characters.
## <P/>
## The <Ref Attr="CASInfo"/> value of <A>tbl</A>, if stored,
## is a list of records, each describing the relation between <A>tbl</A>
## and a character table in the &CAS; library.
## The records have the components
## <List>
## <Mark><C>name</C></Mark>
## <Item>
## the name of the &CAS; table,
## </Item>
## <Mark><C>permchars</C> and <C>permclasses</C></Mark>
## <Item>
## permutations of the <Ref Attr="Irr" BookName="ref"/> values and the
## classes of <A>tbl</A>, respectively, that must be applied in order
## to get the orderings in the original &CAS; table, and
## </Item>
## <Mark><C>text</C></Mark>
## <Item>
## the text that was stored on the &CAS; table
## (which may contain incorrect statements).
## </Item>
## </List>
## <Example>
## gap> tbl:= CharacterTable( "m10" );
## CharacterTable( "A6.2_3" )
## gap> HasCASInfo( tbl );
## true
## gap> CASInfo( tbl );
## [ rec( name := "m10", permchars := (3,5)(4,8,7,6), permclasses := (),
## text := "names: m10\norder: 2^4.3^2.5 = 720\nnumber of c\
## lasses: 8\nsource: cambridge atlas\ncomments: point stabilizer of \
## mathieu-group m11\ntest: orth, min, sym[3]\n" ) ]
## </Example>
## <P/>
## The class fusions stored on tables from the &CAS; library
## have been computed anew with &GAP;;
## the <C>text</C> component of such a fusion record tells if the fusion map
## is equal to that in the &CAS; library,
## up to the permutation of classes between the table in
## &CAS; and its &GAP; version.
## <P/>
## <Example>
## gap> First( ComputedClassFusions( tbl ), x -> x.name = "M11" );
## rec( map := [ 1, 2, 3, 4, 5, 4, 7, 8 ], name := "M11",
## text := "fusion is unique up to table automorphisms,\nthe representa\
## tive is equal to the fusion map on the CAS table" )
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareAttributeSuppCT( "CASInfo", IsNearlyCharacterTable,
[ "character", "class" ] );
#############################################################################
##
#A Maxes( <tbl> )
##
## <#GAPDoc Label="Maxes">
## <ManSection>
## <Attr Name="Maxes" Arg="tbl"/>
##
## <Description>
## If this attribute is set for an ordinary character table <A>tbl</A>
## then the value is a list of identifiers of the ordinary character tables
## of all maximal subgroups of <A>tbl</A>.
## There is no default method to <E>compute</E> this value from <A>tbl</A>.
## <P/>
## If the <Ref Attr="Maxes"/> value of <A>tbl</A> is stored then it lists
## exactly one representative for each conjugacy class of maximal subgroups
## of the group of <A>tbl</A>,
## and the character tables of these maximal subgroups are available in the
## &GAP; Character Table Library,
## and compatible class fusions to <A>tbl</A> are stored on these tables
## (see the example in Section <Ref Subsect="subsect:primpermchars2A6"/>).
## <P/>
## <Example>
## gap> tbl:= CharacterTable( "M11" );;
## gap> HasMaxes( tbl );
## true
## gap> maxes:= Maxes( tbl );
## [ "A6.2_3", "L2(11)", "3^2:Q8.2", "A5.2", "2.S4" ]
## gap> CharacterTable( maxes[1] );
## CharacterTable( "A6.2_3" )
## </Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareAttributeSuppCT( "Maxes", IsNearlyCharacterTable, [] );
#############################################################################
##
#A ConstructionInfoCharacterTable( <tbl> )
##
## <#GAPDoc Label="ConstructionInfoCharacterTable">
## <ManSection>
## <Attr Name="ConstructionInfoCharacterTable" Arg="tbl"/>
##
## <Description>
## If this attribute is set for an ordinary character table <A>tbl</A>
## then the value is a list that describes how this table was constructed.
## The first entry is a string that is the identifier of the function that
## was applied to the pre-table record;
## the remaining entries are the arguments for that function,
## except that the pre-table record must be prepended to these arguments.
## </Description>
## </ManSection>
## <#/GAPDoc>
#T should this be available also for other tables than library tables?
#T (direct products of tables with groups and library tables etc.)
#T and if it is a `SuppCT' attribute then should row/column permutations
#T be always optional arguments to be applied after the constuction?
##
DeclareAttributeSuppCT( "ConstructionInfoCharacterTable",
IsNearlyCharacterTable, [ "character", "class" ] );
#############################################################################
##
#A FusionToTom( <tbl> )
##
## <#GAPDoc Label="FusionToTom">
## <ManSection>
## <Attr Name="FusionToTom" Arg="tbl"/>
##
## <Description>
## If this attribute is set for an ordinary character table <A>tbl</A> then
## the &GAP; Library of Tables of Marks contains the table of marks of the
## group of <A>tbl</A>,
## and the attribute value is a record with the following components.
## <List>
## <Mark><C>name</C></Mark>
## <Item>
## the
## <Ref Attr="Identifier" Label="for tables of marks" BookName="ref"/>
## component of the table of marks of <A>tbl</A>,
## </Item>
## <Mark><C>map</C></Mark>
## <Item>
## the fusion map,
## </Item>
## <Mark><C>text</C> (optional)</Mark>
## <Item>
## a string describing the status of the fusion, and
## </Item>
## <Mark><C>perm</C> (optional)</Mark>
## <Item>
## a permutation that establishes the bijection between the classes of
## maximal subgroups in the table of marks
--> --------------------
--> maximum size reached
--> --------------------
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