Theorem exp43

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

	Ref	Expression
Hypothesis	exp43.1	|- ( ( ( ph /\ ps ) /\ ( ch /\ th ) ) -> ta )
Assertion	exp43	|- ( ph -> ( ps -> ( ch -> ( th -> ta ) ) ) )

Proof

Step	Hyp	Ref	Expression
1		exp43.1	|- ( ( ( ph /\ ps ) /\ ( ch /\ th ) ) -> ta )
2	1	ex	|- ( ( ph /\ ps ) -> ( ( ch /\ th ) -> ta ) )
3	2	exp4b	|- ( ph -> ( ps -> ( ch -> ( th -> ta ) ) ) )