Theorem exp42

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

	Ref	Expression
Hypothesis	exp42.1	|- ( ( ( ph /\ ( ps /\ ch ) ) /\ th ) -> ta )
Assertion	exp42	|- ( ph -> ( ps -> ( ch -> ( th -> ta ) ) ) )

Proof

Step	Hyp	Ref	Expression
1		exp42.1	|- ( ( ( ph /\ ( ps /\ ch ) ) /\ th ) -> ta )
2	1	exp31	|- ( ph -> ( ( ps /\ ch ) -> ( th -> ta ) ) )
3	2	expd	|- ( ph -> ( ps -> ( ch -> ( th -> ta ) ) ) )