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 ) ) |