Metamath Proof Explorer


Theorem xpeq1i

Description: Equality inference for Cartesian product. (Contributed by NM, 21-Dec-2008)

Ref Expression
Hypothesis xpeq1i.1 𝐴 = 𝐵
Assertion xpeq1i ( 𝐴 × 𝐶 ) = ( 𝐵 × 𝐶 )

Proof

Step Hyp Ref Expression
1 xpeq1i.1 𝐴 = 𝐵
2 xpeq1 ( 𝐴 = 𝐵 → ( 𝐴 × 𝐶 ) = ( 𝐵 × 𝐶 ) )
3 1 2 ax-mp ( 𝐴 × 𝐶 ) = ( 𝐵 × 𝐶 )