Metamath Proof Explorer


Theorem dfvd1ir

Description: Inference form of df-vd1 with the virtual deduction as the assertion. (Contributed by Alan Sare, 14-Nov-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis dfvd1ir.1
|- ( ph -> ps )
Assertion dfvd1ir
|- (. ph ->. ps ).

Proof

Step Hyp Ref Expression
1 dfvd1ir.1
 |-  ( ph -> ps )
2 df-vd1
 |-  ( (. ph ->. ps ). <-> ( ph -> ps ) )
3 1 2 mpbir
 |-  (. ph ->. ps ).