Metamath Proof Explorer


Theorem imaeq2i

Description: Equality theorem for image. (Contributed by NM, 21-Dec-2008)

Ref Expression
Hypothesis imaeq1i.1 A = B
Assertion imaeq2i C A = C B

Proof

Step Hyp Ref Expression
1 imaeq1i.1 A = B
2 imaeq2 A = B C A = C B
3 1 2 ax-mp C A = C B