Description: Importation deduction. (Contributed by NM, 31-Mar-1994)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | impd.1 | ⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 → 𝜃 ) ) ) | |
| Assertion | impd | ⊢ ( 𝜑 → ( ( 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | impd.1 | ⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 → 𝜃 ) ) ) | |
| 2 | 1 | com3l | ⊢ ( 𝜓 → ( 𝜒 → ( 𝜑 → 𝜃 ) ) ) |
| 3 | 2 | imp | ⊢ ( ( 𝜓 ∧ 𝜒 ) → ( 𝜑 → 𝜃 ) ) |
| 4 | 3 | com12 | ⊢ ( 𝜑 → ( ( 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |