Theorem prtlem60

Description: Lemma for prter3 . (Contributed by Rodolfo Medina, 9-Oct-2010)

	Ref	Expression
Hypotheses	prtlem60.1	|- ( ph -> ( ps -> ( ch -> th ) ) )
	prtlem60.2	|- ( ps -> ( th -> ta ) )
Assertion	prtlem60	|- ( ph -> ( ps -> ( ch -> ta ) ) )

Proof

Step	Hyp	Ref	Expression
1		prtlem60.1	|- ( ph -> ( ps -> ( ch -> th ) ) )
2		prtlem60.2	|- ( ps -> ( th -> ta ) )
3	2	a1i	|- ( ph -> ( ps -> ( th -> ta ) ) )
4	1 3	syldd	|- ( ph -> ( ps -> ( ch -> ta ) ) )