Description: Equality implies bijection. (Contributed by RP, 9-May-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | cleq1lem | ⊢ ( 𝐴 = 𝐵 → ( ( 𝐴 ⊆ 𝐶 ∧ 𝜑 ) ↔ ( 𝐵 ⊆ 𝐶 ∧ 𝜑 ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | sseq1 | ⊢ ( 𝐴 = 𝐵 → ( 𝐴 ⊆ 𝐶 ↔ 𝐵 ⊆ 𝐶 ) ) | |
| 2 | 1 | anbi1d | ⊢ ( 𝐴 = 𝐵 → ( ( 𝐴 ⊆ 𝐶 ∧ 𝜑 ) ↔ ( 𝐵 ⊆ 𝐶 ∧ 𝜑 ) ) ) |