Theorem pm2.45 750

Description: Theorem *2.45 of [WhiteheadRussell] p. 106. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm2.45	|- ( -. ( ph \/ ps ) -> -. ph )

Proof of Theorem pm2.45

Step	Hyp	Ref	Expression
1		orc 724	. 2 |- ( ph -> ( ph \/ ps ) )
2	1	con3i 641	1 |- ( -. ( ph \/ ps ) -> -. ph )

This proof depends on syntax axioms:   -. wn 3   -> wi 4   \/ wo 720

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-in1 623  ax-in2 624  ax-io 721

This proof depends on definitions:  df-bi 117

This theorem is used by:  pm2.47  752  ioran  764  dn1dc  973  eueq3dc  3000