Theorem 3mix1 815

Description: Introduction in triple disjunction.

Assertion

Ref	Expression
3mix1	|- (ph -> (ph \/ ps \/ ch))

Proof of Theorem 3mix1

Step	Hyp	Ref	Expression
1		orc 269	. 2 |- (ph -> (ph \/ (ps \/ ch)))
2		3orass 778	. 2 |- ((ph \/ ps \/ ch) <-> (ph \/ (ps \/ ch)))
3	1, 2	sylibr 200	1 |- (ph -> (ph \/ ps \/ ch))

Syntax hints:   -> wi 3   \/ wo 222   \/ w3o 774

This theorem is referenced by:  3mix2 816  3mix3 817  tz7.44-1 3928

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7

This theorem depends on definitions:  df-bi 147  df-or 224  df-3or 776

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