Description: Disjunction of three antecedents. (Contributed by NM, 13-Sep-2011) (Proof shortened by Hongxiu Chen, 29-Jun-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 3jaob | ⊢ ( ( ( 𝜑 ∨ 𝜒 ∨ 𝜃 ) → 𝜓 ) ↔ ( ( 𝜑 → 𝜓 ) ∧ ( 𝜒 → 𝜓 ) ∧ ( 𝜃 → 𝜓 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | pm5.53 | ⊢ ( ( ( ( 𝜑 ∨ 𝜒 ) ∨ 𝜃 ) → 𝜓 ) ↔ ( ( ( 𝜑 → 𝜓 ) ∧ ( 𝜒 → 𝜓 ) ) ∧ ( 𝜃 → 𝜓 ) ) ) | |
| 2 | df-3or | ⊢ ( ( 𝜑 ∨ 𝜒 ∨ 𝜃 ) ↔ ( ( 𝜑 ∨ 𝜒 ) ∨ 𝜃 ) ) | |
| 3 | 2 | imbi1i | ⊢ ( ( ( 𝜑 ∨ 𝜒 ∨ 𝜃 ) → 𝜓 ) ↔ ( ( ( 𝜑 ∨ 𝜒 ) ∨ 𝜃 ) → 𝜓 ) ) |
| 4 | df-3an | ⊢ ( ( ( 𝜑 → 𝜓 ) ∧ ( 𝜒 → 𝜓 ) ∧ ( 𝜃 → 𝜓 ) ) ↔ ( ( ( 𝜑 → 𝜓 ) ∧ ( 𝜒 → 𝜓 ) ) ∧ ( 𝜃 → 𝜓 ) ) ) | |
| 5 | 1 3 4 | 3bitr4i | ⊢ ( ( ( 𝜑 ∨ 𝜒 ∨ 𝜃 ) → 𝜓 ) ↔ ( ( 𝜑 → 𝜓 ) ∧ ( 𝜒 → 𝜓 ) ∧ ( 𝜃 → 𝜓 ) ) ) |