Metamath Proof Explorer

Theorem orim1i

Description: Introduce disjunct to both sides of an implication. (Contributed by NM, 6-Jun-1994)

Ref Expression
Hypothesis orim1i.1 
|- ( ph -> ps )
Assertion orim1i 
|- ( ( ph \/ ch ) -> ( ps \/ ch ) )

Proof

Step Hyp Ref Expression
1 orim1i.1 
 |-  ( ph -> ps )
2 id 
 |-  ( ch -> ch )
3 1 2 orim12i 
 |-  ( ( ph \/ ch ) -> ( ps \/ ch ) )