Description: Deduction eliminating a conjunct. (Contributed by NM, 27-May-1998)
Ref | Expression | ||
---|---|---|---|
Hypothesis | simplbi.1 | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) | |
Assertion | simplbi | ⊢ ( 𝜑 → 𝜓 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simplbi.1 | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ) ) | |
2 | 1 | biimpi | ⊢ ( 𝜑 → ( 𝜓 ∧ 𝜒 ) ) |
3 | 2 | simpld | ⊢ ( 𝜑 → 𝜓 ) |