Theorem pm2.46 387

Description: Theorem *2.46 of [WhiteheadRussell] p. 106. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm2.46	|- (-. (ph \/ ps) -> -. ps)

Proof of Theorem pm2.46

Step	Hyp	Ref	Expression
1		olc 373	. 2 |- (ps -> (ph \/ ps))
2	1	con3i 127	1 |- (-. (ph \/ ps) -> -. ps)

Syntax hints:  -. wn 3   -> wi 4   \/ wo 357

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 177  df-or 359

This theorem is referenced by:  pm2.48  389  pm2.49  390  rb-ax3  1519  eueq3  3012