Description: Equality deduction for function value. (Contributed by BJ, 31-Aug-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | fveqeq2 | ⊢ ( 𝐴 = 𝐵 → ( ( 𝐹 ‘ 𝐴 ) = 𝐶 ↔ ( 𝐹 ‘ 𝐵 ) = 𝐶 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | id | ⊢ ( 𝐴 = 𝐵 → 𝐴 = 𝐵 ) | |
2 | 1 | fveqeq2d | ⊢ ( 𝐴 = 𝐵 → ( ( 𝐹 ‘ 𝐴 ) = 𝐶 ↔ ( 𝐹 ‘ 𝐵 ) = 𝐶 ) ) |