Description: Definition of a 3-hypothesis virtual deduction in vd conjunction form. (Contributed by Alan Sare, 13-Jun-2015) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | dfvd3an | ⊢ ( ( ( 𝜑 , 𝜓 , 𝜒 ) ▶ 𝜃 ) ↔ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-vd1 | ⊢ ( ( ( 𝜑 , 𝜓 , 𝜒 ) ▶ 𝜃 ) ↔ ( ( 𝜑 , 𝜓 , 𝜒 ) → 𝜃 ) ) | |
| 2 | df-vhc3 | ⊢ ( ( 𝜑 , 𝜓 , 𝜒 ) ↔ ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) ) | |
| 3 | 2 | imbi1i | ⊢ ( ( ( 𝜑 , 𝜓 , 𝜒 ) → 𝜃 ) ↔ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |
| 4 | 1 3 | bitri | ⊢ ( ( ( 𝜑 , 𝜓 , 𝜒 ) ▶ 𝜃 ) ↔ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |