1 | /*****************************************************************************\ |
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2 | * Computer Algebra System SINGULAR |
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3 | \*****************************************************************************/ |
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4 | /** @file ExtensionInfo.h |
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5 | * |
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6 | * This file provides a class to store information about finite fields and |
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7 | * extensions thereof. |
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8 | * |
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9 | * |
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10 | * @author Martin Lee |
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11 | * |
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12 | * @internal @version \$Id$ |
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13 | * |
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14 | **/ |
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15 | /*****************************************************************************/ |
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16 | |
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17 | #ifndef EXTENSION_INFO_H |
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18 | #define EXTENSION_INFO_H |
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19 | |
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20 | #include <config.h> |
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21 | |
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22 | #include "canonicalform.h" |
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23 | |
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24 | /** @class ExtensionInfo ExtensionInfo.h "factory/ExtensionInfo.h" |
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25 | * ExtensionInfo contains information about extension. |
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26 | * If @a m_extension is true we are in an extension of some initial field. |
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27 | * If the initial field is \f$ F_p \f$ and we pass to \f$ F_p (\alpha) \f$ |
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28 | * then @a m_alpha is an algebraic variable, @a m_beta= Variable(1), |
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29 | * @a m_gamma= @a m_delta= 1, @a m_GFDegree= 0, @a m_GFName= 'Z'. If we pass |
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30 | * to some GF (p^k) then @a m_alpha= Variable (1), @a m_beta= Variable(1), |
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31 | * @a m_gamma= @a m_delta= 1, @a m_GFDegree= 1, @a m_GFName= 'Z'. |
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32 | * @n If the initial field is \f$ F_p (\epsilon) \f$, then @a m_beta= |
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33 | * \f$ \epsilon \f$, @a m_alpha an algebraic variable defining an extension of |
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34 | * \f$ F_p (\epsilon) \f$, @a m_gamma is a primitive element of |
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35 | * \f$ F_p (\alpha) \f$, @a m_delta is a primitive element of |
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36 | * \f$ F_p (\beta) \f$, @a m_GFDegree= 0, @a m_GFName= 'Z'. |
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37 | * @n If the initial field is GF(p^k), then @a m_alpha= Variable (1), |
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38 | * @a m_beta= Variable (1), @a m_gamma= 1, @a m_delta= 1, @a m_GFDegree()= k, |
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39 | * @a m_GFName= gf_name of the initial field. |
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40 | * @n If @a m_extension is false and the current field is \f$ F_p \f$ then |
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41 | * @a m_alpha= Variable (1), @a m_beta= Variable (1), @a m_gamma= 1, |
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42 | * @a m_delta= 1, @a m_GFDegree= 1, @a m_GFName= 'Z'. |
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43 | * @n If the current field is \f$ F_p (\alpha) \f$ then |
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44 | * @a m_alpha is some algebraic variable, @a m_beta= Variable (1), |
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45 | * @a m_gamma= 1, @a m_delta= 1, @a m_GFDegree= 0, @a m_GFName= 'Z'. |
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46 | * @n If the current field is GF then @a m_alpha= Variable (1), |
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47 | * @a m_beta= Variable (1), @a m_gamma= 1, @a m_delta= 1, |
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48 | * @a m_GFDegree= getGFDegree(), @a m_GFName= gf_name. |
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49 | * |
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50 | * @sa facFqBivar.h, facFqFactorize.h |
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51 | */ |
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52 | class ExtensionInfo |
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53 | { |
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54 | private: |
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55 | /// an algebraic variable or Variable (1) |
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56 | Variable m_alpha; |
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57 | /// an algebraic variable or Variable (1) |
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58 | Variable m_beta; |
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59 | /// a primitive element of \f$ F_p (\alpha) \f$ or 1 |
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60 | CanonicalForm m_gamma; |
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61 | /// a primitive element of \f$ F_p (\beta) \f$ or 1 |
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62 | CanonicalForm m_delta; |
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63 | /// GF degree or 1 |
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64 | int m_GFDegree; |
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65 | /// name of GF variable |
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66 | char m_GFName; |
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67 | /// indicates if we are in an extension of some initial field |
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68 | bool m_extension; |
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69 | public: |
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70 | /// \f$ F_p \f$ as initial field, if @a extension is true we are in some GF |
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71 | ExtensionInfo (const bool extension ///< [in] some bool |
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72 | ); |
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73 | /// Construct an @a ExtensionInfo |
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74 | ExtensionInfo (const Variable& alpha, ///< [in] some algebraic variable |
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75 | const Variable& beta, ///< [in] some algebraic variable |
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76 | const CanonicalForm& gamma, ///< [in] some primitive element |
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77 | ///< of \f$ F_p (\alpha) \f$ |
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78 | const CanonicalForm& delta, ///< [in] some primitive element |
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79 | ///< of \f$ F_p (\beta) \f$ |
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80 | const int nGFDegree, ///< [in] GFDegree of initial field |
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81 | const char cGFName, ///< [in] name of GF variable of |
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82 | ///< initial field |
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83 | const bool extension ///< [in] some bool |
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84 | ); |
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85 | /// \f$ F_p (\beta) \f$ as initial field and switch to an extension given by |
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86 | /// @a alpha, needs primitive elements @a gamma and @a delta for maps |
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87 | /// between \f$ F_p (\alpha) \subset F_p (\beta) \f$ |
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88 | ExtensionInfo (const Variable& alpha, ///< [in] some algebraic variable |
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89 | const Variable& beta, ///< [in] some algebraic variable |
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90 | const CanonicalForm& gamma, ///< [in] some primitive element |
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91 | ///< of \f$ F_p (\alpha) \f$ |
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92 | const CanonicalForm& delta ///< [in] some primitive element |
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93 | ///< of \f$ F_p (\beta) \f$ |
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94 | ); |
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95 | /// \f$ F_p (\alpha) \f$ as initial field, if @a extension is false. |
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96 | /// Else initial field is \f$ F_p \f$ |
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97 | ExtensionInfo (const Variable& alpha, ///< [in] some algebraic variable |
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98 | const bool extension ///< [in] some bool |
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99 | ); |
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100 | |
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101 | ExtensionInfo (const Variable& alpha ///< [in] some algebraic variable |
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102 | ); |
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103 | |
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104 | /// GF as initial field |
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105 | ExtensionInfo (const int nGFDegree, ///< [in] GF degree of initial field |
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106 | const char cGFName, ///< [in] name of GF variable |
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107 | const bool extension ///< [in] some bool |
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108 | ); |
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109 | |
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110 | /// getter |
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111 | /// |
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112 | /// @return @a getAlpha() returns @a m_alpha |
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113 | Variable getAlpha () const |
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114 | { |
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115 | return m_alpha; |
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116 | } |
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117 | /// getter |
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118 | /// |
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119 | /// @return @a getBeta() returns @a m_beta |
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120 | Variable getBeta () const |
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121 | { |
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122 | return m_beta; |
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123 | } |
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124 | /// getter |
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125 | /// |
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126 | /// @return @a getGamma() returns @a m_gamma |
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127 | CanonicalForm getGamma() const |
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128 | { |
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129 | return m_gamma; |
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130 | } |
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131 | /// getter |
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132 | /// |
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133 | /// @return @a getDelta() returns @a m_delta |
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134 | CanonicalForm getDelta() const |
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135 | { |
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136 | return m_delta; |
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137 | } |
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138 | /// getter |
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139 | /// |
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140 | /// @return @a getGFDegree() returns @a m_GFDegree |
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141 | int getGFDegree() const |
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142 | { |
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143 | return m_GFDegree; |
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144 | } |
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145 | /// getter |
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146 | /// |
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147 | /// @return @a getGFName() returns @a m_GFName |
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148 | char getGFName() const |
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149 | { |
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150 | return m_GFName; |
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151 | } |
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152 | /// getter |
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153 | /// |
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154 | /// @return @a isInextension() returns @a m_extension |
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155 | bool isInExtension() const |
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156 | { |
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157 | return m_extension; |
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158 | } |
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159 | }; |
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160 | |
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161 | #endif |
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162 | /* EXTENSION_INFO_H */ |
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163 | |
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