Description: Move conjunction outside of biconditional. (Contributed by Mario Carneiro, 11-Sep-2015) (Proof shortened by Wolf Lammen, 19-Jan-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | baib.1 | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) | |
| Assertion | rbaibr | ⊢ ( 𝜒 → ( 𝜓 ↔ 𝜑 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | baib.1 | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) | |
| 2 | 1 | biancomi | ⊢ ( 𝜑 ↔ ( 𝜒 ∧ 𝜓 ) ) |
| 3 | 2 | baibr | ⊢ ( 𝜒 → ( 𝜓 ↔ 𝜑 ) ) |