Metamath Proof Explorer

Theorem imori

Description: Infer disjunction from implication. (Contributed by NM, 12-Mar-2012)

Ref Expression
Hypothesis imori.1 
|- ( ph -> ps )
Assertion imori 
|- ( -. ph \/ ps )

Proof

Step Hyp Ref Expression
1 imori.1 
 |-  ( ph -> ps )
2 imor 
 |-  ( ( ph -> ps ) <-> ( -. ph \/ ps ) )
3 1 2 mpbi 
 |-  ( -. ph \/ ps )