| Quellcodebibliothek Statistik Leitseite products/Sources/formale Sprachen/GAP/pkg/anupq/src/ (Algebra von RWTH Aachen Version 4.15.1©) Datei vom 28.7.2025 mit Größe 1 kB |
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Quelle expand_commutator.c Sprache: C |
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** *A expand_commutator.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 "constants.h" /* routines for handling expansion of commutator relations */ static void add(int *x, int *y); static void invert_symbols(int *x); static int length(int *s); /* expand the commutator of s and t */ void expand_commutator(int *s, int t) { int a[MAXWORD]; register int i; for (i = 0; i < MAXWORD; ++i) a[i] = s[i]; invert_symbols(s); s[length(s)] = -t; add(s, a); s[length(s)] = t; } /* find the number of non-zero entries in s */ static int length(int *s) { register int i = 0; while (i < MAXWORD && s[i] != 0) ++i; return i; } /* concatenate y with x */ static void add(int *x, int *y) { register int j; int i = length(x); for (j = 0; j < MAXWORD && y[j] != 0; ++j) x[i + j] = y[j]; } /* construct the group-theoretic inverse of the symbols in x */ static void invert_symbols(int *x) { register int i = length(x) - 1; register int j; int temp, mid; mid = i / 2; for (j = 0; j <= mid; ++j) { temp = x[j]; x[j] = -x[i - j]; x[i - j] = -temp; } } ¤ Dauer der Verarbeitung: 0.16 Sekunden (vorverarbeitet) ¤*© Formatika GbR, Deutschland |
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2026-03-28