Description: Equality theorem for operation value. (Contributed by NM, 28-Feb-1995)
Ref | Expression | ||
---|---|---|---|
Assertion | oveq2 | ⊢ ( 𝐴 = 𝐵 → ( 𝐶 𝐹 𝐴 ) = ( 𝐶 𝐹 𝐵 ) ) |
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 ) ) |