Theorem 3mix3i

Description: Introduction in triple disjunction. (Contributed by Mario Carneiro, 6-Oct-2014)

	Ref	Expression
Hypothesis	3mixi.1	|- ph
Assertion	3mix3i	|- ( ps \/ ch \/ ph )

Proof

Step	Hyp	Ref	Expression
1		3mixi.1	|- ph
2		3mix3	|- ( ph -> ( ps \/ ch \/ ph ) )
3	1 2	ax-mp	|- ( ps \/ ch \/ ph )