来自汪李峰的问题
设A,B,C,D是任意集合,求证:(A∩B)x(C∩D)=(AxC)∩(BxD)
设A,B,C,D是任意集合,求证:(A∩B)x(C∩D)=(AxC)∩(BxD)
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2020-01-27 00:04
设A,B,C,D是任意集合,求证:(A∩B)x(C∩D)=(AxC)∩(BxD)
设A,B,C,D是任意集合,求证:(A∩B)x(C∩D)=(AxC)∩(BxD)
求证:((A∩B)∪(C∩D)=(A∪C)∩(B∪D)forallx∈(A∩B)∪(C∩D)x∈(A∩B)orx∈(C∩D)(x∈Aandx∈B)or(x∈Candx∈D)(x∈Aorx∈C)and(x∈Borx∈D)x∈(A∪C)andx∈(B∪D)x∈(...