Metamath Proof Explorer


Theorem imaeq2d

Description: Equality theorem for image. (Contributed by FL, 15-Dec-2006)

Ref Expression
Hypothesis imaeq1d.1 ⊢ φ → A = B
Assertion imaeq2d ⊢ φ → C A = C B

Proof

Step Hyp Ref Expression
1 imaeq1d.1 ⊢ φ → A = B
2 imaeq2 ⊢ A = B → C A = C B
3 1 2 syl ⊢ φ → C A = C B