1 | // -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- |
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2 | /*****************************************************************************\ |
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3 | * Computer Algebra System SINGULAR |
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4 | \*****************************************************************************/ |
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5 | /** @file syzextra.cc |
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6 | * |
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7 | * Here we implement the Computation of Syzygies |
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8 | * |
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9 | * ABSTRACT: Computation of Syzygies due to Schreyer |
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10 | * |
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11 | * @author Oleksandr Motsak |
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12 | * |
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13 | **/ |
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14 | /*****************************************************************************/ |
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15 | |
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16 | // include header file |
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17 | #include <kernel/mod2.h> |
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18 | |
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19 | #include "syzextra.h" |
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20 | |
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21 | #include "DebugPrint.h" |
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22 | |
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23 | #include <omalloc/omalloc.h> |
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24 | |
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25 | #include <misc/intvec.h> |
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26 | #include <misc/options.h> |
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27 | |
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28 | #include <coeffs/coeffs.h> |
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29 | |
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30 | #include <polys/monomials/p_polys.h> |
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31 | #include <polys/monomials/ring.h> |
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32 | |
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33 | #include <kernel/kstd1.h> |
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34 | #include <kernel/polys.h> |
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35 | #include <kernel/syz.h> |
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36 | #include <kernel/ideals.h> |
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37 | |
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38 | |
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39 | |
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40 | #include <Singular/tok.h> |
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41 | #include <Singular/ipid.h> |
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42 | #include <Singular/lists.h> |
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43 | #include <Singular/attrib.h> |
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44 | |
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45 | #include <Singular/ipid.h> |
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46 | #include <Singular/ipshell.h> // For iiAddCproc |
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47 | |
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48 | #include <stdio.h> |
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49 | #include <stdlib.h> |
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50 | #include <string.h> |
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51 | |
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52 | // USING_NAMESPACE_SINGULARXX; |
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53 | USING_NAMESPACE( SINGULARXXNAME :: DEBUG ) |
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54 | |
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55 | |
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56 | BEGIN_NAMESPACE_SINGULARXX BEGIN_NAMESPACE(SYZEXTRA) |
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57 | |
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58 | |
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59 | BEGIN_NAMESPACE(SORT_c_ds) |
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60 | |
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61 | |
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62 | #ifdef _GNU_SOURCE |
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63 | static int cmp_c_ds(const void *p1, const void *p2, void *R) |
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64 | { |
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65 | #else |
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66 | static int cmp_c_ds(const void *p1, const void *p2) |
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67 | { |
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68 | void *R = currRing; |
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69 | #endif |
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70 | |
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71 | const int YES = 1; |
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72 | const int NO = -1; |
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73 | |
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74 | const ring r = (const ring) R; // TODO/NOTE: the structure is known: C, lp!!! |
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75 | |
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76 | assume( r == currRing ); |
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77 | |
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78 | const poly a = *(const poly*)p1; |
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79 | const poly b = *(const poly*)p2; |
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80 | |
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81 | assume( a != NULL ); |
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82 | assume( b != NULL ); |
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83 | |
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84 | assume( p_LmTest(a, r) ); |
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85 | assume( p_LmTest(b, r) ); |
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86 | |
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87 | |
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88 | const signed long iCompDiff = p_GetComp(a, r) - p_GetComp(b, r); |
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89 | |
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90 | // TODO: test this!!!!!!!!!!!!!!!! |
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91 | |
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92 | //return -( compare (c, qsorts) ) |
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93 | |
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94 | #ifndef NDEBUG |
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95 | const int __DEBUG__ = 0; |
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96 | if( __DEBUG__ ) |
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97 | { |
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98 | PrintS("cmp_c_ds: a, b: \np1: "); dPrint(a, r, r, 2); |
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99 | PrintS("b: "); dPrint(b, r, r, 2); |
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100 | PrintLn(); |
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101 | } |
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102 | #endif |
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103 | |
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104 | |
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105 | if( iCompDiff > 0 ) |
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106 | return YES; |
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107 | |
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108 | if( iCompDiff < 0 ) |
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109 | return NO; |
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110 | |
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111 | assume( iCompDiff == 0 ); |
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112 | |
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113 | const signed long iDegDiff = p_Totaldegree(a, r) - p_Totaldegree(b, r); |
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114 | |
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115 | if( iDegDiff > 0 ) |
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116 | return YES; |
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117 | |
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118 | if( iDegDiff < 0 ) |
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119 | return NO; |
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120 | |
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121 | assume( iDegDiff == 0 ); |
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122 | |
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123 | #ifndef NDEBUG |
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124 | if( __DEBUG__ ) |
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125 | { |
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126 | PrintS("cmp_c_ds: a & b have the same comp & deg! "); PrintLn(); |
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127 | } |
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128 | #endif |
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129 | |
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130 | for (int v = rVar(r); v > 0; v--) |
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131 | { |
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132 | assume( v > 0 ); |
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133 | assume( v <= rVar(r) ); |
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134 | |
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135 | const signed int d = p_GetExp(a, v, r) - p_GetExp(b, v, r); |
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136 | |
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137 | if( d > 0 ) |
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138 | return YES; |
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139 | |
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140 | if( d < 0 ) |
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141 | return NO; |
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142 | |
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143 | assume( d == 0 ); |
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144 | } |
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145 | |
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146 | return 0; |
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147 | } |
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148 | |
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149 | END_NAMESPACE |
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150 | /* namespace SORT_c_ds */ |
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151 | |
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152 | /// return a new term: leading coeff * leading monomial of p |
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153 | /// with 0 leading component! |
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154 | poly leadmonom(const poly p, const ring r) |
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155 | { |
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156 | poly m = NULL; |
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157 | |
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158 | if( p != NULL ) |
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159 | { |
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160 | assume( p != NULL ); |
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161 | assume( p_LmTest(p, r) ); |
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162 | |
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163 | m = p_LmInit(p, r); |
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164 | p_SetCoeff0(m, n_Copy(p_GetCoeff(p, r), r), r); |
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165 | |
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166 | p_SetComp(m, 0, r); |
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167 | p_Setm(m, r); |
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168 | |
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169 | assume( p_GetComp(m, r) == 0 ); |
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170 | assume( m != NULL ); |
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171 | assume( pNext(m) == NULL ); |
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172 | assume( p_LmTest(m, r) ); |
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173 | } |
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174 | |
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175 | return m; |
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176 | } |
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177 | |
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178 | |
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179 | |
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180 | poly p_Tail(const poly p, const ring r) |
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181 | { |
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182 | if( p == NULL) |
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183 | return NULL; |
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184 | else |
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185 | return p_Copy( pNext(p), r ); |
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186 | } |
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187 | |
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188 | |
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189 | ideal id_Tail(const ideal id, const ring r) |
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190 | { |
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191 | if( id == NULL) |
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192 | return NULL; |
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193 | |
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194 | const ideal newid = idInit(IDELEMS(id),id->rank); |
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195 | |
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196 | for (int i=IDELEMS(id) - 1; i >= 0; i--) |
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197 | newid->m[i] = p_Tail( id->m[i], r ); |
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198 | |
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199 | newid->rank = id_RankFreeModule(newid, currRing); |
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200 | |
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201 | return newid; |
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202 | } |
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203 | |
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204 | |
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205 | |
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206 | void Sort_c_ds(const ideal id, const ring r) |
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207 | { |
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208 | const int sizeNew = IDELEMS(id); |
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209 | |
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210 | #ifdef _GNU_SOURCE |
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211 | #define qsort_my(m, s, ss, r, cmp) qsort_r(m, s, ss, cmp, r) |
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212 | #else |
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213 | #define qsort_my(m, s, ss, r, cmp) qsort_r(m, s, ss, cmp) |
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214 | #endif |
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215 | |
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216 | if( sizeNew >= 2 ) |
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217 | qsort_my(id->m, sizeNew, sizeof(poly), r, FROM_NAMESPACE(SORT_c_ds, cmp_c_ds)); |
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218 | |
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219 | #undef qsort_my |
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220 | |
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221 | id->rank = id_RankFreeModule(id, r); |
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222 | } |
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223 | |
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224 | |
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225 | BEGIN_NAMESPACE(INTERNAL) |
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226 | |
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227 | ideal _ComputeLeadingSyzygyTerms(const ideal& id, |
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228 | const ring r, |
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229 | const SchreyerSyzygyComputationFlags attributes) |
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230 | { |
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231 | // const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
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232 | // const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
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233 | const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
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234 | // const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
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235 | // const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
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236 | |
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237 | assume(!__LEAD2SYZ__); |
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238 | |
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239 | // 1. set of components S? |
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240 | // 2. for each component c from S: set of indices of leading terms |
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241 | // with this component? |
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242 | // 3. short exp. vectors for each leading term? |
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243 | |
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244 | const int size = IDELEMS(id); |
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245 | |
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246 | if( size < 2 ) |
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247 | { |
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248 | const ideal newid = idInit(1, 0); newid->m[0] = NULL; // zero ideal... |
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249 | return newid; |
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250 | } |
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251 | |
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252 | |
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253 | // TODO/NOTE: input is supposed to be (reverse-) sorted wrt "(c,ds)"!?? |
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254 | |
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255 | // components should come in groups: count elements in each group |
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256 | // && estimate the real size!!! |
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257 | |
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258 | |
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259 | // use just a vector instead??? |
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260 | const ideal newid = idInit( (size * (size-1))/2, size); // maximal size: ideal case! |
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261 | |
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262 | int k = 0; |
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263 | |
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264 | for (int j = 0; j < size; j++) |
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265 | { |
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266 | const poly p = id->m[j]; |
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267 | assume( p != NULL ); |
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268 | const int c = p_GetComp(p, r); |
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269 | |
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270 | for (int i = j - 1; i >= 0; i--) |
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271 | { |
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272 | const poly pp = id->m[i]; |
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273 | assume( pp != NULL ); |
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274 | const int cc = p_GetComp(pp, r); |
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275 | |
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276 | if( c != cc ) |
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277 | continue; |
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278 | |
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279 | const poly m = p_Init(r); // p_New??? |
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280 | |
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281 | // m = LCM(p, pp) / p! // TODO: optimize: knowing the ring structure: (C/lp)! |
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282 | for (int v = rVar(r); v > 0; v--) |
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283 | { |
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284 | assume( v > 0 ); |
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285 | assume( v <= rVar(r) ); |
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286 | |
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287 | const short e1 = p_GetExp(p , v, r); |
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288 | const short e2 = p_GetExp(pp, v, r); |
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289 | |
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290 | if( e1 >= e2 ) |
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291 | p_SetExp(m, v, 0, r); |
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292 | else |
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293 | p_SetExp(m, v, e2 - e1, r); |
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294 | |
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295 | } |
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296 | |
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297 | assume( (j > i) && (i >= 0) ); |
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298 | |
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299 | p_SetComp(m, j + 1, r); |
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300 | pNext(m) = NULL; |
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301 | p_SetCoeff0(m, n_Init(1, r->cf), r); // for later... |
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302 | |
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303 | p_Setm(m, r); // should not do anything!!! |
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304 | |
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305 | newid->m[k++] = m; |
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306 | } |
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307 | } |
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308 | |
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309 | // if( __DEBUG__ && FALSE ) |
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310 | // { |
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311 | // PrintS("ComputeLeadingSyzygyTerms::Temp0: \n"); |
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312 | // dPrint(newid, r, r, 1); |
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313 | // } |
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314 | |
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315 | // the rest of newid is assumed to be zeroes... |
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316 | |
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317 | // simplify(newid, 2 + 32)?? |
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318 | // sort(newid, "C,ds")[1]??? |
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319 | id_DelDiv(newid, r); // #define SIMPL_LMDIV 32 |
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320 | |
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321 | // if( __DEBUG__ && FALSE ) |
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322 | // { |
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323 | // PrintS("ComputeLeadingSyzygyTerms::Temp1: \n"); |
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324 | // dPrint(newid, r, r, 1); |
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325 | // } |
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326 | |
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327 | idSkipZeroes(newid); // #define SIMPL_NULL 2 |
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328 | |
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329 | // if( __DEBUG__ ) |
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330 | // { |
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331 | // PrintS("ComputeLeadingSyzygyTerms::Output: \n"); |
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332 | // dPrint(newid, r, r, 1); |
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333 | // } |
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334 | |
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335 | Sort_c_ds(newid, r); |
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336 | |
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337 | return newid; |
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338 | } |
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339 | |
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340 | ideal _Compute2LeadingSyzygyTerms(const ideal& id, |
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341 | const ring r, |
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342 | const SchreyerSyzygyComputationFlags attributes) |
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343 | { |
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344 | // const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
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345 | // const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
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346 | // const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
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347 | // const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
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348 | const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
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349 | |
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350 | |
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351 | // 1. set of components S? |
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352 | // 2. for each component c from S: set of indices of leading terms |
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353 | // with this component? |
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354 | // 3. short exp. vectors for each leading term? |
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355 | |
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356 | const int size = IDELEMS(id); |
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357 | |
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358 | if( size < 2 ) |
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359 | { |
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360 | const ideal newid = idInit(1, 1); newid->m[0] = NULL; // zero module... |
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361 | return newid; |
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362 | } |
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363 | |
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364 | |
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365 | // TODO/NOTE: input is supposed to be sorted wrt "C,ds"!?? |
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366 | |
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367 | // components should come in groups: count elements in each group |
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368 | // && estimate the real size!!! |
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369 | |
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370 | |
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371 | // use just a vector instead??? |
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372 | ideal newid = idInit( (size * (size-1))/2, size); // maximal size: ideal case! |
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373 | |
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374 | int k = 0; |
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375 | |
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376 | for (int j = 0; j < size; j++) |
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377 | { |
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378 | const poly p = id->m[j]; |
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379 | assume( p != NULL ); |
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380 | const int c = p_GetComp(p, r); |
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381 | |
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382 | for (int i = j - 1; i >= 0; i--) |
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383 | { |
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384 | const poly pp = id->m[i]; |
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385 | assume( pp != NULL ); |
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386 | const int cc = p_GetComp(pp, r); |
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387 | |
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388 | if( c != cc ) |
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389 | continue; |
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390 | |
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391 | // allocate memory & zero it out! |
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392 | const poly m = p_Init(r); const poly mm = p_Init(r); |
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393 | |
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394 | |
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395 | // m = LCM(p, pp) / p! mm = LCM(p, pp) / pp! |
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396 | // TODO: optimize: knowing the ring structure: (C/lp)! |
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397 | |
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398 | for (int v = rVar(r); v > 0; v--) |
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399 | { |
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400 | assume( v > 0 ); |
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401 | assume( v <= rVar(r) ); |
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402 | |
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403 | const short e1 = p_GetExp(p , v, r); |
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404 | const short e2 = p_GetExp(pp, v, r); |
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405 | |
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406 | if( e1 >= e2 ) |
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407 | p_SetExp(mm, v, e1 - e2, r); // p_SetExp(m, v, 0, r); |
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408 | else |
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409 | p_SetExp(m, v, e2 - e1, r); // p_SetExp(mm, v, 0, r); |
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410 | |
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411 | } |
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412 | |
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413 | assume( (j > i) && (i >= 0) ); |
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414 | |
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415 | p_SetComp(m, j + 1, r); |
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416 | p_SetComp(mm, i + 1, r); |
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417 | |
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418 | const number& lc1 = p_GetCoeff(p , r); |
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419 | const number& lc2 = p_GetCoeff(pp, r); |
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420 | |
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421 | number g = n_Lcm( lc1, lc2, r ); |
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422 | |
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423 | p_SetCoeff0(m , n_Div(g, lc1, r), r); |
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424 | p_SetCoeff0(mm, n_Neg(n_Div(g, lc2, r), r), r); |
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425 | |
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426 | n_Delete(&g, r); |
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427 | |
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428 | p_Setm(m, r); // should not do anything!!! |
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429 | p_Setm(mm, r); // should not do anything!!! |
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430 | |
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431 | pNext(m) = mm; // pNext(mm) = NULL; |
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432 | |
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433 | newid->m[k++] = m; |
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434 | } |
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435 | } |
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436 | |
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437 | // if( __DEBUG__ && FALSE ) |
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438 | // { |
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439 | // PrintS("Compute2LeadingSyzygyTerms::Temp0: \n"); |
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440 | // dPrint(newid, r, r, 1); |
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441 | // } |
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442 | |
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443 | if( !__TAILREDSYZ__ ) |
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444 | { |
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445 | // simplify(newid, 2 + 32)?? |
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446 | // sort(newid, "C,ds")[1]??? |
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447 | id_DelDiv(newid, r); // #define SIMPL_LMDIV 32 |
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448 | |
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449 | // if( __DEBUG__ && FALSE ) |
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450 | // { |
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451 | // PrintS("Compute2LeadingSyzygyTerms::Temp1 (deldiv): \n"); |
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452 | // dPrint(newid, r, r, 1); |
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453 | // } |
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454 | } |
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455 | else |
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456 | { |
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457 | // option(redSB); option(redTail); |
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458 | // TEST_OPT_REDSB |
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459 | // TEST_OPT_REDTAIL |
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460 | assume( r == currRing ); |
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461 | BITSET _save_test = test; |
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462 | test |= (Sy_bit(OPT_REDTAIL) | Sy_bit(OPT_REDSB)); |
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463 | |
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464 | intvec* w=new intvec(IDELEMS(newid)); |
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465 | ideal tmp = kStd(newid, currQuotient, isHomog, &w); |
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466 | delete w; |
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467 | |
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468 | test = _save_test; |
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469 | |
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470 | id_Delete(&newid, r); |
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471 | newid = tmp; |
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472 | |
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473 | // if( __DEBUG__ && FALSE ) |
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474 | // { |
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475 | // PrintS("Compute2LeadingSyzygyTerms::Temp1 (std): \n"); |
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476 | // dPrint(newid, r, r, 1); |
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477 | // } |
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478 | |
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479 | } |
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480 | |
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481 | idSkipZeroes(newid); |
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482 | |
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483 | Sort_c_ds(newid, r); |
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484 | |
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485 | return newid; |
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486 | } |
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487 | |
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488 | poly _FindReducer(poly product, poly syzterm, |
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489 | ideal L, ideal LS, |
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490 | const ring r, |
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491 | const SchreyerSyzygyComputationFlags attributes) |
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492 | { |
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493 | const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
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494 | const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
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495 | // const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
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496 | // const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
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497 | // const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
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498 | |
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499 | assume( product != NULL ); |
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500 | assume( L != NULL ); |
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501 | |
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502 | int c = 0; |
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503 | |
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504 | if (syzterm != NULL) |
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505 | c = p_GetComp(syzterm, r) - 1; |
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506 | |
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507 | assume( c >= 0 && c < IDELEMS(L) ); |
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508 | |
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509 | if (__SYZCHECK__ && syzterm != NULL) |
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510 | { |
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511 | const poly m = L->m[c]; |
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512 | |
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513 | assume( m != NULL ); assume( pNext(m) == NULL ); |
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514 | |
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515 | poly lm = p_Mult_mm(leadmonom(syzterm, r), m, r); |
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516 | assume( p_EqualPolys(lm, product, r) ); |
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517 | |
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518 | // def @@c = leadcomp(syzterm); int @@r = int(@@c); |
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519 | // def @@product = leadmonomial(syzterm) * L[@@r]; |
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520 | |
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521 | p_Delete(&lm, r); |
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522 | } |
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523 | |
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524 | // looking for an appropriate diviser q = L[k]... |
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525 | for( int k = IDELEMS(L)-1; k>= 0; k-- ) |
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526 | { |
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527 | const poly p = L->m[k]; |
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528 | |
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529 | // ... which divides the product, looking for the _1st_ appropriate one! |
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530 | if( !p_LmDivisibleBy(p, product, r) ) |
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531 | continue; |
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532 | |
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533 | |
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534 | const poly q = p_New(r); |
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535 | pNext(q) = NULL; |
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536 | p_ExpVectorDiff(q, product, p, r); // (LM(product) / LM(L[k])) |
---|
537 | p_SetComp(q, k + 1, r); |
---|
538 | p_Setm(q, r); |
---|
539 | |
---|
540 | // cannot allow something like: a*gen(i) - a*gen(i) |
---|
541 | if (syzterm != NULL && (k == c)) |
---|
542 | if (p_ExpVectorEqual(syzterm, q, r)) |
---|
543 | { |
---|
544 | if( __DEBUG__ ) |
---|
545 | { |
---|
546 | Print("_FindReducer::Test SYZTERM: q == syzterm !:((, syzterm is: "); |
---|
547 | dPrint(syzterm, r, r, 1); |
---|
548 | } |
---|
549 | |
---|
550 | p_LmFree(q, r); |
---|
551 | continue; |
---|
552 | } |
---|
553 | |
---|
554 | // while the complement (the fraction) is not reducible by leading syzygies |
---|
555 | if( LS != NULL ) |
---|
556 | { |
---|
557 | BOOLEAN ok = TRUE; |
---|
558 | |
---|
559 | for(int kk = IDELEMS(LS)-1; kk>= 0; kk-- ) |
---|
560 | { |
---|
561 | const poly pp = LS->m[kk]; |
---|
562 | |
---|
563 | if( p_LmDivisibleBy(pp, q, r) ) |
---|
564 | { |
---|
565 | |
---|
566 | if( __DEBUG__ ) |
---|
567 | { |
---|
568 | Print("_FindReducer::Test LS: q is divisible by LS[%d] !:((, diviser is: ", kk+1); |
---|
569 | dPrint(pp, r, r, 1); |
---|
570 | } |
---|
571 | |
---|
572 | ok = FALSE; // q in <LS> :(( |
---|
573 | break; |
---|
574 | } |
---|
575 | } |
---|
576 | |
---|
577 | if(!ok) |
---|
578 | { |
---|
579 | p_LmFree(q, r); |
---|
580 | continue; |
---|
581 | } |
---|
582 | } |
---|
583 | |
---|
584 | p_SetCoeff0(q, n_Neg( n_Div( p_GetCoeff(product, r), p_GetCoeff(p, r), r), r), r); |
---|
585 | return q; |
---|
586 | |
---|
587 | } |
---|
588 | |
---|
589 | |
---|
590 | return NULL; |
---|
591 | } |
---|
592 | |
---|
593 | poly _ReduceTerm(poly multiplier, poly term4reduction, poly syztermCheck, |
---|
594 | ideal L, ideal T, ideal LS, |
---|
595 | const ring r, const SchreyerSyzygyComputationFlags attributes); |
---|
596 | |
---|
597 | poly _TraverseTail(poly multiplier, poly tail, |
---|
598 | ideal L, ideal T, ideal LS, |
---|
599 | const ring r, |
---|
600 | const SchreyerSyzygyComputationFlags attributes) |
---|
601 | { |
---|
602 | // const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
---|
603 | // const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
---|
604 | // const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
---|
605 | // const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
---|
606 | // const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
---|
607 | |
---|
608 | assume( multiplier != NULL ); |
---|
609 | |
---|
610 | assume( L != NULL ); |
---|
611 | assume( T != NULL ); |
---|
612 | |
---|
613 | poly s = NULL; |
---|
614 | |
---|
615 | // iterate over the tail |
---|
616 | for(poly p = tail; p != NULL; p = pNext(p)) |
---|
617 | s = p_Add_q(s, _ReduceTerm(multiplier, p, NULL, L, T, LS, r, attributes), r); |
---|
618 | |
---|
619 | return s; |
---|
620 | } |
---|
621 | |
---|
622 | |
---|
623 | poly _ReduceTerm(poly multiplier, poly term4reduction, poly syztermCheck, |
---|
624 | ideal L, ideal T, ideal LS, |
---|
625 | const ring r, |
---|
626 | const SchreyerSyzygyComputationFlags attributes) |
---|
627 | { |
---|
628 | // const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
---|
629 | // const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
---|
630 | // const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
---|
631 | // const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
---|
632 | // const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
---|
633 | |
---|
634 | assume( multiplier != NULL ); |
---|
635 | assume( term4reduction != NULL ); |
---|
636 | |
---|
637 | |
---|
638 | assume( L != NULL ); |
---|
639 | assume( T != NULL ); |
---|
640 | |
---|
641 | // assume(r == currRing); // ? |
---|
642 | |
---|
643 | // simple implementation with FindReducer: |
---|
644 | poly s = NULL; |
---|
645 | |
---|
646 | if(1) |
---|
647 | { |
---|
648 | // NOTE: only LT(term4reduction) should be used in the following: |
---|
649 | poly product = pp_Mult_mm(multiplier, term4reduction, r); |
---|
650 | s = _FindReducer(product, syztermCheck, L, LS, r, attributes); |
---|
651 | p_Delete(&product, r); |
---|
652 | } |
---|
653 | |
---|
654 | if( s == NULL ) // No Reducer? |
---|
655 | return s; |
---|
656 | |
---|
657 | poly b = leadmonom(s, r); |
---|
658 | |
---|
659 | const int c = p_GetComp(s, r) - 1; |
---|
660 | assume( c >= 0 && c < IDELEMS(T) ); |
---|
661 | |
---|
662 | const poly tail = T->m[c]; |
---|
663 | |
---|
664 | if( tail != NULL ) |
---|
665 | s = p_Add_q(s, _TraverseTail(b, tail, L, T, LS, r, attributes), r); |
---|
666 | |
---|
667 | return s; |
---|
668 | } |
---|
669 | |
---|
670 | |
---|
671 | poly _SchreyerSyzygyNF(poly syz_lead, poly syz_2, |
---|
672 | ideal L, ideal T, ideal LS, |
---|
673 | const ring r, |
---|
674 | const SchreyerSyzygyComputationFlags attributes) |
---|
675 | { |
---|
676 | // const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
---|
677 | // const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
---|
678 | // const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
---|
679 | // const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
---|
680 | // const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
---|
681 | |
---|
682 | assume( syz_lead != NULL ); |
---|
683 | assume( syz_2 != NULL ); |
---|
684 | |
---|
685 | assume( L != NULL ); |
---|
686 | assume( T != NULL ); |
---|
687 | |
---|
688 | assume( IDELEMS(L) == IDELEMS(T) ); |
---|
689 | |
---|
690 | int c = p_GetComp(syz_lead, r) - 1; |
---|
691 | |
---|
692 | assume( c >= 0 && c < IDELEMS(T) ); |
---|
693 | |
---|
694 | poly p = leadmonom(syz_lead, r); // :( |
---|
695 | poly spoly = pp_Mult_qq(p, T->m[c], r); |
---|
696 | p_Delete(&p, r); |
---|
697 | |
---|
698 | |
---|
699 | c = p_GetComp(syz_2, r) - 1; |
---|
700 | assume( c >= 0 && c < IDELEMS(T) ); |
---|
701 | |
---|
702 | p = leadmonom(syz_2, r); // :( |
---|
703 | spoly = p_Add_q(spoly, pp_Mult_qq(p, T->m[c], r), r); |
---|
704 | p_Delete(&p, r); |
---|
705 | |
---|
706 | poly tail = p_Copy(syz_2, r); // TODO: use bucket!? |
---|
707 | |
---|
708 | while (spoly != NULL) |
---|
709 | { |
---|
710 | poly t = _FindReducer(spoly, NULL, L, LS, r, attributes); |
---|
711 | |
---|
712 | p_LmDelete(&spoly, r); |
---|
713 | |
---|
714 | if( t != NULL ) |
---|
715 | { |
---|
716 | p = leadmonom(t, r); // :( |
---|
717 | c = p_GetComp(t, r) - 1; |
---|
718 | |
---|
719 | assume( c >= 0 && c < IDELEMS(T) ); |
---|
720 | |
---|
721 | spoly = p_Add_q(spoly, pp_Mult_qq(p, T->m[c], r), r); |
---|
722 | |
---|
723 | p_Delete(&p, r); |
---|
724 | |
---|
725 | tail = p_Add_q(tail, t, r); |
---|
726 | } |
---|
727 | } |
---|
728 | |
---|
729 | return tail; |
---|
730 | } |
---|
731 | |
---|
732 | |
---|
733 | void _ComputeSyzygy(const ideal L, const ideal T, |
---|
734 | ideal& LL, ideal& TT, |
---|
735 | const ring R, |
---|
736 | const SchreyerSyzygyComputationFlags attributes) |
---|
737 | { |
---|
738 | // const BOOLEAN __DEBUG__ = attributes.__DEBUG__; |
---|
739 | // const BOOLEAN __SYZCHECK__ = attributes.__SYZCHECK__; |
---|
740 | const BOOLEAN __LEAD2SYZ__ = attributes.__LEAD2SYZ__; |
---|
741 | const BOOLEAN __HYBRIDNF__ = attributes.__HYBRIDNF__; |
---|
742 | const BOOLEAN __TAILREDSYZ__ = attributes.__TAILREDSYZ__; |
---|
743 | |
---|
744 | assume( R == currRing ); // For attributes :-/ |
---|
745 | |
---|
746 | assume( IDELEMS(L) == IDELEMS(T) ); |
---|
747 | |
---|
748 | if( __LEAD2SYZ__ ) |
---|
749 | LL = _Compute2LeadingSyzygyTerms(L, R, attributes); // 2 terms! |
---|
750 | else |
---|
751 | LL = _ComputeLeadingSyzygyTerms(L, R, attributes); // 1 term! |
---|
752 | |
---|
753 | const int size = IDELEMS(LL); |
---|
754 | |
---|
755 | TT = idInit(size, 0); |
---|
756 | |
---|
757 | if( size == 1 && LL->m[0] == NULL ) |
---|
758 | return; |
---|
759 | |
---|
760 | |
---|
761 | ideal LS = NULL; |
---|
762 | |
---|
763 | if( __TAILREDSYZ__ ) |
---|
764 | LS = LL; |
---|
765 | |
---|
766 | for( int k = size - 1; k >= 0; k-- ) |
---|
767 | { |
---|
768 | const poly a = LL->m[k]; assume( a != NULL ); |
---|
769 | |
---|
770 | const int r = p_GetComp(a, R) - 1; |
---|
771 | |
---|
772 | assume( r >= 0 && r < IDELEMS(T) ); |
---|
773 | assume( r >= 0 && r < IDELEMS(L) ); |
---|
774 | |
---|
775 | poly aa = leadmonom(a, R); assume( aa != NULL); // :( |
---|
776 | |
---|
777 | poly a2 = pNext(a); |
---|
778 | |
---|
779 | if( a2 != NULL ) |
---|
780 | { |
---|
781 | TT->m[k] = a2; pNext(a) = NULL; |
---|
782 | } |
---|
783 | |
---|
784 | if( ! __HYBRIDNF__ ) |
---|
785 | { |
---|
786 | poly t = _TraverseTail(aa, T->m[r], L, T, LS, R, attributes); |
---|
787 | |
---|
788 | if( a2 != NULL ) |
---|
789 | { |
---|
790 | assume( __LEAD2SYZ__ ); |
---|
791 | |
---|
792 | const int r2 = p_GetComp(a2, R) - 1; poly aa2 = leadmonom(a2, R); // :( |
---|
793 | |
---|
794 | assume( r2 >= 0 && r2 < IDELEMS(T) ); |
---|
795 | |
---|
796 | TT->m[k] = p_Add_q(a2, p_Add_q(t, _TraverseTail(aa2, T->m[r2], L, T, LS, R, attributes), R), R); |
---|
797 | |
---|
798 | p_Delete(&aa2, R); |
---|
799 | } else |
---|
800 | TT->m[k] = p_Add_q(t, _ReduceTerm(aa, L->m[r], a, L, T, LS, R, attributes), R); |
---|
801 | |
---|
802 | } else |
---|
803 | { |
---|
804 | if( a2 == NULL ) |
---|
805 | { |
---|
806 | aa = p_Mult_mm(aa, L->m[r], R); |
---|
807 | a2 = _FindReducer(aa, a, L, LS, R, attributes); |
---|
808 | } |
---|
809 | assume( a2 != NULL ); |
---|
810 | |
---|
811 | TT->m[k] = _SchreyerSyzygyNF(a, a2, L, T, LS, R, attributes); // will copy a2 :( |
---|
812 | |
---|
813 | p_Delete(&a2, R); |
---|
814 | } |
---|
815 | p_Delete(&aa, R); |
---|
816 | } |
---|
817 | |
---|
818 | TT->rank = id_RankFreeModule(TT, R); |
---|
819 | } |
---|
820 | |
---|
821 | END_NAMESPACE |
---|
822 | |
---|
823 | |
---|
824 | // TODO: wrapper layer, just for now... dissolve! |
---|
825 | |
---|
826 | void SchreyerSyzygyComputation::ComputeSyzygy() |
---|
827 | { |
---|
828 | /// assumes m_syzLeads == m_syzTails == NULL! |
---|
829 | FROM_NAMESPACE(INTERNAL, _ComputeSyzygy(m_idLeads, m_idTails, m_syzLeads, m_syzTails, m_rBaseRing, m_atttributes)); // TODO: just a wrapper for now :/ |
---|
830 | } |
---|
831 | |
---|
832 | void SchreyerSyzygyComputation::ComputeLeadingSyzygyTerms(bool bComputeSecondTerms) |
---|
833 | { |
---|
834 | if( bComputeSecondTerms ) |
---|
835 | m_syzLeads = FROM_NAMESPACE(INTERNAL, _Compute2LeadingSyzygyTerms(m_idLeads, m_rBaseRing, m_atttributes)); |
---|
836 | else |
---|
837 | m_syzLeads = FROM_NAMESPACE(INTERNAL, _ComputeLeadingSyzygyTerms(m_idLeads, m_rBaseRing, m_atttributes)); |
---|
838 | |
---|
839 | // NOTE: set m_LS if tails are to be reduced! |
---|
840 | } |
---|
841 | |
---|
842 | poly SchreyerSyzygyComputation::FindReducer(poly product, poly syzterm) const |
---|
843 | { |
---|
844 | return FROM_NAMESPACE(INTERNAL, _FindReducer(product, syzterm, m_idLeads, m_LS, m_rBaseRing, m_atttributes)); |
---|
845 | } |
---|
846 | |
---|
847 | poly SchreyerSyzygyComputation::SchreyerSyzygyNF(poly syz_lead, poly syz_2) const |
---|
848 | { |
---|
849 | return FROM_NAMESPACE(INTERNAL, _SchreyerSyzygyNF(syz_lead, syz_2, m_idLeads, m_idTails, m_LS, m_rBaseRing, m_atttributes)); |
---|
850 | } |
---|
851 | |
---|
852 | poly SchreyerSyzygyComputation::TraverseTail(poly multiplier, poly tail) const |
---|
853 | { |
---|
854 | return FROM_NAMESPACE(INTERNAL, _TraverseTail(multiplier, tail, m_idLeads, m_idTails, m_LS, m_rBaseRing, m_atttributes)); |
---|
855 | } |
---|
856 | |
---|
857 | poly SchreyerSyzygyComputation::ReduceTerm(poly multiplier, poly term4reduction, poly syztermCheck) const |
---|
858 | { |
---|
859 | return FROM_NAMESPACE(INTERNAL, _ReduceTerm(multiplier, term4reduction, syztermCheck, m_idLeads, m_idTails, m_LS, m_rBaseRing, m_atttributes)); |
---|
860 | } |
---|
861 | |
---|
862 | |
---|
863 | BEGIN_NAMESPACE_NONAME |
---|
864 | |
---|
865 | static inline int atGetInt(idhdl rootRingHdl, const char* attribute, int def) |
---|
866 | { |
---|
867 | return ((int)(long)(atGet(rootRingHdl, attribute, INT_CMD, (void*)def))); |
---|
868 | } |
---|
869 | |
---|
870 | END_NAMESPACE |
---|
871 | |
---|
872 | SchreyerSyzygyComputationFlags::SchreyerSyzygyComputationFlags(idhdl rootRingHdl): |
---|
873 | #ifndef NDEBUG |
---|
874 | __DEBUG__( (BOOLEAN)atGetInt(rootRingHdl,"DEBUG", TRUE) ), |
---|
875 | #else |
---|
876 | __DEBUG__( (BOOLEAN)atGetInt(rootRingHdl,"DEBUG", FALSE) ), |
---|
877 | #endif |
---|
878 | __SYZCHECK__( (BOOLEAN)atGetInt(rootRingHdl, "SYZCHECK", __DEBUG__) ), |
---|
879 | __LEAD2SYZ__( (BOOLEAN)atGetInt(rootRingHdl, "LEAD2SYZ", 1) ), |
---|
880 | __TAILREDSYZ__( (BOOLEAN)atGetInt(rootRingHdl, "TAILREDSYZ", 1) ), |
---|
881 | __HYBRIDNF__( (BOOLEAN)atGetInt(rootRingHdl, "HYBRIDNF", 0) ) |
---|
882 | { |
---|
883 | if( __DEBUG__ ) |
---|
884 | { |
---|
885 | PrintS("SchreyerSyzygyComputationFlags: \n"); |
---|
886 | Print(" DEBUG : \t%d\n", __DEBUG__); |
---|
887 | Print(" SYZCHECK : \t%d\n", __SYZCHECK__); |
---|
888 | Print(" LEAD2SYZ : \t%d\n", __LEAD2SYZ__); |
---|
889 | Print(" TAILREDSYZ: \t%d\n", __TAILREDSYZ__); |
---|
890 | } |
---|
891 | |
---|
892 | // TODO: just current setting! |
---|
893 | assume( rootRingHdl == currRingHdl ); |
---|
894 | assume( rootRingHdl->typ == RING_CMD ); |
---|
895 | assume( rootRingHdl->data.uring == currRing ); |
---|
896 | // move the global ring here inside??? |
---|
897 | } |
---|
898 | |
---|
899 | |
---|
900 | |
---|
901 | |
---|
902 | END_NAMESPACE END_NAMESPACE_SINGULARXX |
---|
903 | |
---|
904 | |
---|
905 | // Vi-modeline: vim: filetype=c:syntax:shiftwidth=2:tabstop=8:textwidth=0:expandtab |
---|