Theorem 3mix1i

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

	Ref	Expression
Hypothesis	3mixi.1	|- ph
Assertion	3mix1i	|- ( ph \/ ps \/ ch )

Proof

Step	Hyp	Ref	Expression
1		3mixi.1	|- ph
2		3mix1	|- ( ph -> ( ph \/ ps \/ ch ) )
3	1 2	ax-mp	|- ( ph \/ ps \/ ch )