Metamath Proof Explorer


Theorem oveq2

Description: Equality theorem for operation value. (Contributed by NM, 28-Feb-1995)

Ref Expression
Assertion oveq2 ( 𝐴 = 𝐵 → ( 𝐶 𝐹 𝐴 ) = ( 𝐶 𝐹 𝐵 ) )

Proof

Step Hyp Ref Expression
1 opeq2 ( 𝐴 = 𝐵 → ⟨ 𝐶 , 𝐴 ⟩ = ⟨ 𝐶 , 𝐵 ⟩ )
2 1 fveq2d ( 𝐴 = 𝐵 → ( 𝐹 ‘ ⟨ 𝐶 , 𝐴 ⟩ ) = ( 𝐹 ‘ ⟨ 𝐶 , 𝐵 ⟩ ) )
3 df-ov ( 𝐶 𝐹 𝐴 ) = ( 𝐹 ‘ ⟨ 𝐶 , 𝐴 ⟩ )
4 df-ov ( 𝐶 𝐹 𝐵 ) = ( 𝐹 ‘ ⟨ 𝐶 , 𝐵 ⟩ )
5 2 3 4 3eqtr4g ( 𝐴 = 𝐵 → ( 𝐶 𝐹 𝐴 ) = ( 𝐶 𝐹 𝐵 ) )