Metamath Proof Explorer


Theorem vd01

Description: A virtual hypothesis virtually infers a theorem. (Contributed by Alan Sare, 14-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis vd01.1 𝜑
Assertion vd01 (    𝜓    ▶    𝜑    )

Proof

Step Hyp Ref Expression
1 vd01.1 𝜑
2 1 a1i ( 𝜓𝜑 )
3 2 dfvd1ir (    𝜓    ▶    𝜑    )