Copyright 2000 Centre for Discrete Mathematics and Computing, Department of Mathematics and Department of Computer Science & Electrical Engineering, The University of Queensland, QLD 4072. (http://staff.itee.uq.edu.au/havas)
This is the header file for Level 1 of ACE; that is, a set of basic wrapper routines round the core enumerator. This can also be thought of as a simple interface between application programmes (eg, ACE Level 2) and the clever bits.
#define LLL 75 /* Approx limit on output line length */
/****************************************************************** The memory for the coset table is currently allocated as one contiguous block. This is done by the user; Level 1 expects to be `handed' the workspace for the table, pointed to by costable. DEFWORK should be used as the default number of words (i.e., entries) in toto. The size is indicated via a size/multiplier combination (workspace/workmult). The usual K/M/G multipliers are used, with a choice of meanings to suit computer scientists, or engineers, or mathematicians. The default (under pressure) is to use powers of 10. While coset numbers are limited to 2G, table sizes can exceed the 32-bit limit. tabsiz indicates the maximum number of rows which can (safely) be fitted into the allocated space (depends on ncol); if this works out to less than 2, the _start() function will complain.
******************************************************************/
#define DEFWORK 1000000
#ifdef AL1_BINARY # define KILO 1024 # define MEGA 1048576 # define GIGA 1073741824 #else # define KILO 1000 # define MEGA 1000000 # define GIGA 1000000000 #endif
/****************************************************************** The group relations and subgroup generators are stored as linked lists. Each item on the list consists of an array of generators (i.e., the word), along with its total length, its exponent & whether or not it was enter as x^2 (ie, as an involn). In the words, -ve numbers represent inverses. The word starts at word[1]. Each list has a header containing the list's length and head/tail pointers.
******************************************************************/
typedefstruct Wlelt
{ int *word; /* array of generators */ int len, exp; /* total length, and exponent */
Logic invol; /* ?entered as an involution */ struct Wlelt *next; /* next in list */
}
Wlelt; /* word list element */
typedefstruct
{ int len; /* list length */
Wlelt *first, *last; /* head & tail of list */
}
Wlist; /* word list */
/****************************************************************** We find coset rep's by backtracing the table. currrep is the currently active rep've, repsiz is its size & repsp is the space allocated to currrep. Note that the rep is in terms of columns!
******************************************************************/
externint *currrep, repsiz, repsp;
/****************************************************************** Logic control variables for current enumeration.
******************************************************************/
extern Logic asis; /* TRUE: use presentation as given. FALSE:
reduce/reorder relations/generators. */
/****************************************************************** Group stuff:
******************************************************************/
externchar *grpname; /* Enumeration (i.e., group) name */ extern Wlist *rellst; /* The group's relator list */ externint trellen; /* Total list length */
externint ndgen; /* Number of group generators */ extern Logic *geninv; /* Are generators involutions? */ externint *gencol; /* Translates +/- gen'r nos to columns */ externint *colgen; /* col nos to +/- gen'r nos */
extern Logic galpha; /* True if the generators are letters */ externchar algen[28]; /* Translate generator number (1..ndgen, in its order of entry) to its letter (ie, 'a'...'z').
A printable string, hence 1+26+1=28 posns! */ externint genal[27]; /* Translate generator letter (where a=1,
etc) to its order of entry (ie, number). */
externchar *subgrpname; /* Subgroup name */ extern Wlist *genlst; /* The subgroup's renerator list */ externint tgenlen; /* Total list length */
/****************************************************************** Many of the Level 0 parameters can be set directly. However, some of them have slightly different meanings at Level 1 (eg, a special value can be used to indicate a `default'), or can effect a continuing enumeration. All of the following variables are `aliases' for Level 0 parameters, and it is up to the _start() function to decide when & how they should be transferred to their Level 0 namesakes.
******************************************************************/
/****************************************************************** Externally visible functions defined in util1.c
******************************************************************/
/****************************************************************** Externally visible functions defined in control.c
******************************************************************/
int al1_start(int);
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