Theorem exp5k

Description: An exportation inference. (Contributed by Jeff Hankins, 7-Jul-2009)

	Ref	Expression
Hypothesis	exp5k.1	|- ( ph -> ( ( ( ps /\ ( ch /\ th ) ) /\ ta ) -> et ) )
Assertion	exp5k	|- ( ph -> ( ps -> ( ch -> ( th -> ( ta -> et ) ) ) ) )

Proof

Step	Hyp	Ref	Expression
1		exp5k.1	|- ( ph -> ( ( ( ps /\ ( ch /\ th ) ) /\ ta ) -> et ) )
2	1	expd	|- ( ph -> ( ( ps /\ ( ch /\ th ) ) -> ( ta -> et ) ) )
3	2	exp4d	|- ( ph -> ( ps -> ( ch -> ( th -> ( ta -> et ) ) ) ) )