Metamath Proof Explorer


Theorem funbrafvb

Description: Equivalence of function value and binary relation, analogous to funbrfvb . (Contributed by Alexander van der Vekens, 25-May-2017)

Ref Expression
Assertion funbrafvb ( ( Fun 𝐹𝐴 ∈ dom 𝐹 ) → ( ( 𝐹 ''' 𝐴 ) = 𝐵𝐴 𝐹 𝐵 ) )

Proof

Step Hyp Ref Expression
1 funfn ( Fun 𝐹𝐹 Fn dom 𝐹 )
2 fnbrafvb ( ( 𝐹 Fn dom 𝐹𝐴 ∈ dom 𝐹 ) → ( ( 𝐹 ''' 𝐴 ) = 𝐵𝐴 𝐹 𝐵 ) )
3 1 2 sylanb ( ( Fun 𝐹𝐴 ∈ dom 𝐹 ) → ( ( 𝐹 ''' 𝐴 ) = 𝐵𝐴 𝐹 𝐵 ) )