Metamath Proof Explorer

Theorem pm1.4

Description: Axiom *1.4 of WhiteheadRussell p. 96. (Contributed by NM, 3-Jan-2005)

Ref Expression
Assertion pm1.4 
|- ( ( ph \/ ps ) -> ( ps \/ ph ) )

Proof

Step Hyp Ref Expression
1 olc 
 |-  ( ph -> ( ps \/ ph ) )
2 orc 
 |-  ( ps -> ( ps \/ ph ) )
3 1 2 jaoi 
 |-  ( ( ph \/ ps ) -> ( ps \/ ph ) )