Theorem exp4d

Description: An exportation inference. (Contributed by NM, 26-Apr-1994)

	Ref	Expression
Hypothesis	exp4d.1	|- ( ph -> ( ( ps /\ ( ch /\ th ) ) -> ta ) )
Assertion	exp4d	|- ( ph -> ( ps -> ( ch -> ( th -> ta ) ) ) )

Proof

Step	Hyp	Ref	Expression
1		exp4d.1	|- ( ph -> ( ( ps /\ ( ch /\ th ) ) -> ta ) )
2	1	expd	|- ( ph -> ( ps -> ( ( ch /\ th ) -> ta ) ) )
3	2	exp4a	|- ( ph -> ( ps -> ( ch -> ( th -> ta ) ) ) )