Description: Distribution of implication over biconditional (inference form). (Contributed by NM, 1-Aug-1994)
Ref | Expression | ||
---|---|---|---|
Hypothesis | pm5.74i.1 | ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) | |
Assertion | pm5.74i | ⊢ ( ( 𝜑 → 𝜓 ) ↔ ( 𝜑 → 𝜒 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pm5.74i.1 | ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) | |
2 | pm5.74 | ⊢ ( ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) ↔ ( ( 𝜑 → 𝜓 ) ↔ ( 𝜑 → 𝜒 ) ) ) | |
3 | 1 2 | mpbi | ⊢ ( ( 𝜑 → 𝜓 ) ↔ ( 𝜑 → 𝜒 ) ) |