Description: Deduce an implication from a logical equivalence. Deduction associated with biimp and biimpi . (Contributed by NM, 11-Jan-1993)
Ref | Expression | ||
---|---|---|---|
Hypothesis | biimpd.1 | ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) | |
Assertion | biimpd | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | biimpd.1 | ⊢ ( 𝜑 → ( 𝜓 ↔ 𝜒 ) ) | |
2 | biimp | ⊢ ( ( 𝜓 ↔ 𝜒 ) → ( 𝜓 → 𝜒 ) ) | |
3 | 1 2 | syl | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) |