Quelle commute_dgen.c Sprache: C

/****************************************************************************
**
*A  commute_dgen.c              ANUPQ source                   Eamonn O'Brien
**
*Y  Copyright 1995-2001,  Lehrstuhl D fuer Mathematik,  RWTH Aachen,  Germany
*Y  Copyright 1995-2001,  School of Mathematical Sciences, ANU,     Australia
**
*/

#include "pq_defs.h"
#include "pcp_vars.h"
#include "constants.h"
#include "pq_functions.h"
#include "pretty_filterfns.h"
#include "word_types.h"

static void
collect_defining_generator_word(int ptr, int cp, struct pcp_vars *pcp);

/* calculate a power of a left-normed commutator of supplied depth
   by repeated calls to find_commutator; set up the result as an
   exponent vector with base address pcp->lused in order to permit
   the result to be handed to echelon easily; each component
   is a defining generator */

void commute_defining_generators(int format, struct pcp_vars *pcp)
{
   register int *y = y_address;

   register int ptr, cp1, cp2, cp3, cp4, result;
   register int lastg = pcp->lastg;
   register int total;
   int disp = 0;
   int type;
   int depth;
   int exp;

   total = 6 * lastg + 6;
   if (is_space_exhausted(total, pcp))
      return;

   cp1 = pcp->submlg - lastg - 2;
   cp2 = cp1 - lastg;
   cp3 = cp2 - lastg;
   cp4 = cp3 - lastg;
   result = cp4 - lastg;
   ptr = pcp->lused + 1;

   /* fudge the value of submlg because of possible call to power */
   pcp->submlg -= total;

   read_value(TRUE, "Input number of components of commutator: ", &depth, 2);

   /* read in a and set it up at cp2 and cp3 */
   type = FIRST_ENTRY;

   if (format == BASIC)
      read_word(stdin, disp, type, pcp);
   else
      pretty_read_word(stdin, disp, type, pcp);

   collect_defining_generator_word(ptr, cp2, pcp);
   copy(cp2, lastg, cp3, pcp);

   type = NEXT_ENTRY;
   disp = y[ptr] + 1;

   while (--depth > 0) {

      /* read in next component, b, and set it up at cp1 and cp4 */
      if (format == BASIC)
         read_word(stdin, disp, type, pcp);
      else
         pretty_read_word(stdin, disp, type, pcp);

      collect_defining_generator_word(ptr + disp, cp1, pcp);
      copy(cp1, lastg, cp4, pcp);

      /* solve the equation (ba) * x = ab to obtain [a, b] */
      find_commutator(cp1, cp2, cp3, cp4, result, pcp);

      copy(result, lastg, cp2, pcp);
      copy(result, lastg, cp3, pcp);
   }

   read_value(TRUE, "Input required power of this commutator: ", &exp, 1);
   power(exp, result, pcp);

   /* print the commutator */
   setup_word_to_print("commutator", result, ptr, pcp);

   /* copy result to pcp->lused */
   copy(result, lastg, pcp->lused, pcp);

   /* reset the value of submlg */
   pcp->submlg += total;
}

/* collect word in defining generators stored as string at
   y[ptr] and place the result as exponent vector at cp */

static void
collect_defining_generator_word(int ptr, int cp, struct pcp_vars *pcp)
{
   register int *y = y_address;

   int i, generator, genval;
#if defined(DEBUG)
   int j, word_len;
#endif
   int length, exp;
   register int lastg = pcp->lastg;

   /* zero out lastg entries in array in order to store result */
   for (i = 1; i <= lastg; ++i)
      y[cp + i] = 0;

   length = y[ptr];
   for (i = 1; i < length; ++i) {
      generator = y[ptr + 1 + i];
      genval = y[pcp->dgen + generator];

#if defined(DEBUG)
      if (genval > 0)
         printf("%d %d\n", generator, genval);
      else if (genval < 0) {
         printf("%d %d ", generator, y[-genval]);
         word_len = y[-genval + 1];
         for (j = 1; j <= word_len; ++j)
            printf(" %d", y[-genval + 1 + j]);
      };
      if (genval == 0)
         printf("No defining generator %d -- taken to be the identity\n",
                generator);
#endif

      collect(genval, cp, pcp);
   }

   /* calculate power of this word */
   exp = y[ptr + 1];
   power(exp, cp, pcp);

#if defined(DEBUG)
   print_array(y, cp, cp + pcp->lastg + 1);
#endif
}

/* prepare to collect word in defining generators */

void setup_defgen_word_to_collect(
    FILE *file, int format, int type, int cp, struct pcp_vars *pcp)
{
   int disp = pcp->lastg + 2;
   register int ptr;

   ptr = pcp->lused + 1 + disp;

   if (format == BASIC)
      read_word(file, disp, type, pcp);
   else
      pretty_read_word(file, disp, type, pcp);

   collect_defining_generator_word(ptr, cp, pcp);

   if (type == ACTION || file != stdin)
      return;

   setup_word_to_print("result of collection", cp, ptr, pcp);
}

quality92%

¤ Dauer der Verarbeitung: 0.22 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.