Theorem orcnd

Description: A lemma for Conjunctive Normal Form unit propagation, in deduction form. (Contributed by Giovanni Mascellani, 15-Sep-2017)

	Ref	Expression
Hypotheses	orcnd.1	|- ( ph -> ( ps \/ ch ) )
	orcnd.2	|- ( ph -> -. ps )
Assertion	orcnd	|- ( ph -> ch )

Proof

Step	Hyp	Ref	Expression
1		orcnd.1	|- ( ph -> ( ps \/ ch ) )
2		orcnd.2	|- ( ph -> -. ps )
3	1	orcomd	|- ( ph -> ( ch \/ ps ) )
4	3 2	olcnd	|- ( ph -> ch )