Description: Deduction eliminating a conjunct. A translation of natural deduction rule /\ EL ( /\ elimination left), see natded . (Contributed by NM, 26-May-1993)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | simpld.1 | ⊢ ( 𝜑 → ( 𝜓 ∧ 𝜒 ) ) | |
| Assertion | simpld | ⊢ ( 𝜑 → 𝜓 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpld.1 | ⊢ ( 𝜑 → ( 𝜓 ∧ 𝜒 ) ) | |
| 2 | simpl | ⊢ ( ( 𝜓 ∧ 𝜒 ) → 𝜓 ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → 𝜓 ) |