Theorem pm3.13 487

Description: Theorem *3.13 of [WhiteheadRussell] p. 111. (Contributed by NM, 3-Jan-2005.)

Assertion

Ref	Expression
pm3.13	|- (-. (ph /\ ps) -> (-. ph \/ -. ps))

Proof of Theorem pm3.13

Step	Hyp	Ref	Expression
1		pm3.11 485	. 2 |- (-. (-. ph \/ -. ps) -> (ph /\ ps))
2	1	con1i 121	1 |- (-. (ph /\ ps) -> (-. ph \/ -. ps))

This proof depends on syntax axioms:  -. wn 3   -> wi 4   \/ wo 357   /\ wa 358

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This proof depends on definitions:  df-bi 177  df-or 359  df-an 360

This theorem is used by: (None)