笛卡儿积 笛卡儿积运算具有以下性质 性质4:对并和交运算满足分配律,即 (1)A×(BUO)=(A×B)∪U(A×C (2)(BUC)XA=(B×A)U(C×A) (3)A×(B∩C)=(4×B)n(A×C) (4)(BnC×A=(B×A)n(C×A)6 笛卡儿积 z 笛卡儿积运算具有以下性质: ¾ 性质4: 对并和交运算满足分配律, 即 (1) A × (B∪C) = (A × B)∪(A × C) (2) (B∪C) × A = (B × A)∪(C × A) (3) A × (B∩C) = (A × B)∩(A × C) (4) (B∩C) × A = (B × A)∩(C × A)