Description: Alternate proof of 3jcad . (Contributed by Hongxiu Chen, 29-Jun-2025) (Proof modification is discouraged.) Use 3jcad instead. (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | 3jcadALT.1 | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) | |
| 3jcadALT.2 | ⊢ ( 𝜑 → ( 𝜓 → 𝜃 ) ) | ||
| 3jcadALT.3 | ⊢ ( 𝜑 → ( 𝜓 → 𝜏 ) ) | ||
| Assertion | 3jcadALT | ⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 ∧ 𝜃 ∧ 𝜏 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 3jcadALT.1 | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) | |
| 2 | 3jcadALT.2 | ⊢ ( 𝜑 → ( 𝜓 → 𝜃 ) ) | |
| 3 | 3jcadALT.3 | ⊢ ( 𝜑 → ( 𝜓 → 𝜏 ) ) | |
| 4 | 1 2 | jcad | ⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 ∧ 𝜃 ) ) ) |
| 5 | 4 3 | jcad | ⊢ ( 𝜑 → ( 𝜓 → ( ( 𝜒 ∧ 𝜃 ) ∧ 𝜏 ) ) ) |
| 6 | df-3an | ⊢ ( ( 𝜒 ∧ 𝜃 ∧ 𝜏 ) ↔ ( ( 𝜒 ∧ 𝜃 ) ∧ 𝜏 ) ) | |
| 7 | 5 6 | imbitrrdi | ⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 ∧ 𝜃 ∧ 𝜏 ) ) ) |