Theorem adantl

Description: Inference adding a conjunct to the left of an antecedent. (Contributed by NM, 30-Aug-1993) (Proof shortened by Wolf Lammen, 23-Nov-2012)

	Ref	Expression
Hypothesis	adantl.1	|- ( ph -> ps )
Assertion	adantl	|- ( ( ch /\ ph ) -> ps )

Proof

Step	Hyp	Ref	Expression
1		adantl.1	|- ( ph -> ps )
2	1	adantr	|- ( ( ph /\ ch ) -> ps )
3	2	ancoms	|- ( ( ch /\ ph ) -> ps )