Theorem ori 364

Description: Infer implication from disjunction. (Contributed by NM, 11-Jun-1994.)

Hypothesis

Ref	Expression
ori.1	|- (ph \/ ps)

Assertion

Ref	Expression
ori	|- (-. ph -> ps)

Proof of Theorem ori

Step	Hyp	Ref	Expression
1		ori.1	. 2 |- (ph \/ ps)
2		df-or 359	. 2 |- ((ph \/ ps) <-> (-. ph -> ps))
3	1, 2	mpbi 199	1 |- (-. ph -> 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:  3ori  1242  mtp-or  1538  moexex  2273  mo2icl  3016  mosubopt  4613