Description: Deduce a conjunct from a triple conjunction. (Contributed by Jonathan Ben-Naim, 3-Jun-2011)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | 3simp1bi.1 | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ∧ 𝜃 ) ) | |
| Assertion | simp2bi | ⊢ ( 𝜑 → 𝜒 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 3simp1bi.1 | ⊢ ( 𝜑 ↔ ( 𝜓 ∧ 𝜒 ∧ 𝜃 ) ) | |
| 2 | 1 | biimpi | ⊢ ( 𝜑 → ( 𝜓 ∧ 𝜒 ∧ 𝜃 ) ) |
| 3 | 2 | simp2d | ⊢ ( 𝜑 → 𝜒 ) |