Theorem simplld

Description: Deduction form of simpll , eliminating a double conjunct. (Contributed by Glauco Siliprandi, 11-Dec-2019)

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

Proof

Step	Hyp	Ref	Expression
1		simplld.1	|- ( ph -> ( ( ps /\ ch ) /\ th ) )
2	1	simpld	|- ( ph -> ( ps /\ ch ) )
3	2	simpld	|- ( ph -> ps )