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
|- ph
Assertion vd01
|- (. ps ->. ph ).

Proof

Step Hyp Ref Expression
1 vd01.1
 |-  ph
2 1 a1i
 |-  ( ps -> ph )
3 2 dfvd1ir
 |-  (. ps ->. ph ).