Metamath Proof Explorer


Theorem funeqd

Description: Equality deduction for the function predicate. (Contributed by NM, 23-Feb-2013)

Ref Expression
Hypothesis funeqd.1 ( 𝜑𝐴 = 𝐵 )
Assertion funeqd ( 𝜑 → ( Fun 𝐴 ↔ Fun 𝐵 ) )

Proof

Step Hyp Ref Expression
1 funeqd.1 ( 𝜑𝐴 = 𝐵 )
2 funeq ( 𝐴 = 𝐵 → ( Fun 𝐴 ↔ Fun 𝐵 ) )
3 1 2 syl ( 𝜑 → ( Fun 𝐴 ↔ Fun 𝐵 ) )