Metamath Proof Explorer


Theorem cdeqi

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

Ref Expression
Hypothesis cdeqi.1 ( 𝑥 = 𝑦𝜑 )
Assertion cdeqi CondEq ( 𝑥 = 𝑦𝜑 )

Proof

Step Hyp Ref Expression
1 cdeqi.1 ( 𝑥 = 𝑦𝜑 )
2 df-cdeq ( CondEq ( 𝑥 = 𝑦𝜑 ) ↔ ( 𝑥 = 𝑦𝜑 ) )
3 1 2 mpbir CondEq ( 𝑥 = 𝑦𝜑 )