Description: Two virtual hypotheses virtually infer a theorem. (Contributed by Alan Sare, 14-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | vd02.1 | ⊢ 𝜑 | |
Assertion | vd02 | ⊢ ( 𝜓 , 𝜒 ▶ 𝜑 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | vd02.1 | ⊢ 𝜑 | |
2 | 1 | a1i | ⊢ ( 𝜒 → 𝜑 ) |
3 | 2 | a1i | ⊢ ( 𝜓 → ( 𝜒 → 𝜑 ) ) |
4 | 3 | dfvd2ir | ⊢ ( 𝜓 , 𝜒 ▶ 𝜑 ) |