Metamath Proof Explorer


Theorem cdeqi

Description: Deduce conditional equality. (Contributed by Mario Carneiro, 11-Aug-2016)

Ref Expression
Hypothesis cdeqi.1 ⊢ x = y → φ
Assertion cdeqi ⊢ CondEq x = y → φ

Proof

Step Hyp Ref Expression
1 cdeqi.1 ⊢ x = y → φ
2 df-cdeq ⊢ CondEq x = y → φ ↔ x = y → φ
3 1 2 mpbir ⊢ CondEq x = y → φ