Metamath Proof Explorer


Theorem ixpeq1d

Description: Equality theorem for infinite Cartesian product. (Contributed by Mario Carneiro, 11-Jun-2016)

Ref Expression
Hypothesis ixpeq1d.1 φ A = B
Assertion ixpeq1d φ x A C = x B C

Proof

Step Hyp Ref Expression
1 ixpeq1d.1 φ A = B
2 ixpeq1 A = B x A C = x B C
3 1 2 syl φ x A C = x B C