Theorem pm4.42r 973

Description: One direction of Theorem *4.42 of [WhiteheadRussell] p. 119. (Contributed by Jim Kingdon, 4-Aug-2018.)

Assertion

Ref	Expression
pm4.42r	|- ( ( ( ph /\ ps ) \/ ( ph /\ -. ps ) ) -> ph )

Proof of Theorem pm4.42r

Step	Hyp	Ref	Expression
1		simpl 109	. 2 |- ( ( ph /\ ps ) -> ph )
2		simpl 109	. 2 |- ( ( ph /\ -. ps ) -> ph )
3	1, 2	jaoi 717	1 |- ( ( ( ph /\ ps ) \/ ( ph /\ -. ps ) ) -> ph )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   \/ wo 709

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 710

This theorem depends on definitions:  df-bi 117

This theorem is referenced by: (None)