Theorem 3mix3d

Description: Deduction introducing triple disjunction. (Contributed by Scott Fenton, 8-Jun-2011)

	Ref	Expression
Hypothesis	3mixd.1	|- ( ph -> ps )
Assertion	3mix3d	|- ( ph -> ( ch \/ th \/ ps ) )

Proof

Step	Hyp	Ref	Expression
1		3mixd.1	|- ( ph -> ps )
2		3mix3	|- ( ps -> ( ch \/ th \/ ps ) )
3	1 2	syl	|- ( ph -> ( ch \/ th \/ ps ) )