影響因素決策表，如下表2所示。
[0037] 2-2)計算決策表中條件屬性的等價類關(guān)系集合即IND⑵（Pg /?),以及求解正域 即P〇Sp (P) = U，并根據(jù)粗糙集理論的不可分辨關(guān)系判別條件屬性是否是條件屬性R的相對 約簡，若不是則不對該條件屬性進(jìn)行約簡；若是則進(jìn)行下一步，判別該條件屬性是否可以同 時約簡、還是其中部分條件屬性可以約簡。
[0038] 對于政治風(fēng)險A來說，決策表S=<U，A>，其中論域U= {1，2,3,......,67}, 條件屬性A = {Ay A2, A3, A4, A5, AJ。根據(jù)粗糙集等價類集合以及正域的定義，求出條件屬性 A的相關(guān)等價類集合和正域，結(jié)果如下：
[0039] Posa(A) = U
[0040] U/Ind(A)
[0041] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8}，{9}，{10}，{11，36}，{12}，{13}，{14}， {15}， {16}， {17,37,46}， {18,61}， {19}， {20}， {21}， {22}， {23,39}， {24}， {25,64}， {26}， { 27}， {28}， {29}， {30}， {31}， {32,56}， {33}， {34}， {35}， {38}， {40}， {41}， {42}， {43}， {44} ，{45}， {47}， {48}， {49,54}， {50}， {51}， {52}， {53}， {55}， {57}， {58}， {59}， {60}， {62}， {6 3}， {65}， {66}， {67}};
[0042] U/Ind(A- {Aj)
[0043] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8}，{9}，{10}，{11，36}，{12}，{13}，{14}， {15}， {16}， {17,37,46,51}， {18,61}， {19,27}， {20}， {21}， {22}， {23,39}， {24}， {25,64}， {26}， {28}， {29}， {30}， {31，58}， {32,56}， {33}， {34}， {35}， {38}， {40}， {41}， {42}， {43}， {44}， {45}， {47}， {48}， {49, 54}， {50}， {52}， {53}， {55}， {57}， {59}， {60}， {62}， {63}， {65 }， {66}， {67}};
[0044] U/Ind(A_{A2})
[0045] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8}，{9}，{10}，{11，36}，{12}，{13}，{14}， {15}， {16}， {17,37,46}， {18,61}， {19}， {20}， {21}， {22,44}， {23,39,58}， {24}， {25,64}， {26}， {27}， {28}， {29}， {30}， {31}， {32,56}， {33}， {34}， {35}， {38}， {40}， {41}， {42}， {43 }， {45}， {47}， {48}， {49,54}， {50}， {51}， {52}， {53}， {55}， {57}， {59}， {60}， {62}， {63}， { 65}， {66}， {67}};
[0046] U/Ind(A_{A3})
[0047] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8}，{9}，{10}，{11，23, 36, 39}}，{12}，{13 }, {14}, {15}, {16}, {17,37,46}, {18, 33,61}, {19,60}, {20}, {21}, {22}, {24}, {25}, {26} ，{27}， {28}， {29}， {30,50}， {31}， {32,56}， {34}， {35}， {38}， {40}， {41}， {42}， {43}， {44} ，{45}， {47}， {48}， {49,54}， {51}， {52}， {53}， {55}， {57}， {58}， {59}， {62}， {63}， {64}， {6 5}， {66}， {67}};
[0048] U/ind(A_{A4})
[0049] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8}，{9}，{10}，{11，36}，{12}，{13}，{14}， {15}， {16}， {17,37,46}， {18,61}， {19}， {20}， {21}， {22}， {23,39}， {24}， {25,64}， {26}， { 27}， {28}， {29}， {30}， {31}， {32,56}， {33}， {34}， {35}， {38}， {40}， {41}， {42}， {43}， {44} ，{45}， {47}， {48}， {49,54}， {50}， {51}， {52}， {53}， {55}， {57}， {58}， {59}， {60}， {62}， {6 3}， {65}， {66}， {67}};
[0050] U/ind(A-{A5})
[0051] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8}，{9}，{10}，{11，36}，{12}，{13}，{14}， {15}， {16}， {17,37,46}， {18,61}， {19}， {20}， {21}， {22}， {23,39}， {24}， {25,64}， {26}， { 27}， {28}， {29}， {30}， {31}， {32,56}， {33}， {34}， {35}， {38}， {40}， {41}， {42}， {43}， {44} ，{45}， {47}， {48}， {49,54}， {50}， {51}， {52}， {53}， {55}， {57}， {58}， {59}， {60}， {62}， {6 3}， {65}， {66}， {67}};
[0052] U/ind(A-{A6})
[0053] = {{1}，{2}，{3}，{4}，{5}，{6}，{7}，{8, 32, 56}，{9}，{10}，{11，36}，{12}，{13} ,{14}, {15}, {16}, {17, 25,37,46,64}, {18,61}, {19}, {20}, {21}, {22,49, 54}, {23, 39}, { 24,31}, {26}, {27}, {28}, {29}, {30}, {33}, {34, 59}, {35}, {38}, {40}, {41}, {42}, {43}, { 44}, {45,66}, {47}, {48}, {50}, {51}, {52}, {53}, {55}, {57}, {58}, {60}, {62}, {63}, {65} ,{67}}；
[0054] Posa(A) = U
[0055] P〇s(A {A1})
[0056] = {{1, 4, 8, 12, 16}, {2, 36, 40}, {3}, {5, 6, 7, 28, 62}, {9}, {10, 14, 17, 26}, {11}, {13, 15, 18, 43}, {19, 33, 47}, {20, 25, 32, 44, 49}, {21}, {22, 27, 37, 55, 56}, {23, 24, 61}, {2 9, 30, 41, 64, 65}, {31, 39, 46, 57, 59}, {34, 48, 51, 52, 54, 63, 66}, {35, 50, 58}, {38, 53, 60}, {42,45}, {67}}；
[0057] Pos(A _ (A)
[0058] = {{1, 3, 59}, {2, 6}, {4, 7, 14, 22, 39}, {5, 8, 12, 23, 24, 42}, {9, 11, 13, 44}, {10, 19, 29}, {15, 26, 46}, {16, 28, 47, 56}, {17, 51}, {18, 33, 36, 50, 64}, {20, 49, 55, 60}, {21, 57 ,67}, {25, 30, 45, 54, 63}, {27, 62} {31, 58, 61} {32, 43}, {34}, {35}, {37, 48, 52}, {38}, {40, 53}, {41}, {65}, {66}}；
[0059] Pos(A _ (A)
[0060] = {{1}, {2, 33, 40, 50}, {3, 18, 46, 48}, {4, 21, 53}, {5, 7, 10, 38, 54}, {6, 35, 52, 6 7}, {8}, {9}, {11}, {12, 29,45,62}, {13,27}, {14,26,44}, {15, 28,60}, {16,31,47}, {17,32 }, {19, 34,49}, {20,61}, {22,57}, {23,42,63}, {24}, {25}, {30}, {36}, {37,59}, {39}, {41} ,{43,65}, {51,56}, {55}, {58}}；
[0061] Pos(A{A4})⑷
[0062] = {{1}, {