Description: Definition of a 3-hypothesis virtual deduction. (Contributed by Alan Sare, 14-Nov-2011) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | df-vd3 | ⊢ ( ( 𝜑 , 𝜓 , 𝜒 ▶ 𝜃 ) ↔ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | wph | ⊢ 𝜑 | |
1 | wps | ⊢ 𝜓 | |
2 | wch | ⊢ 𝜒 | |
3 | wth | ⊢ 𝜃 | |
4 | 0 1 2 3 | wvd3 | ⊢ ( 𝜑 , 𝜓 , 𝜒 ▶ 𝜃 ) |
5 | 0 1 2 | w3a | ⊢ ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) |
6 | 5 3 | wi | ⊢ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) → 𝜃 ) |
7 | 4 6 | wb | ⊢ ( ( 𝜑 , 𝜓 , 𝜒 ▶ 𝜃 ) ↔ ( ( 𝜑 ∧ 𝜓 ∧ 𝜒 ) → 𝜃 ) ) |