Theorem jc

Description: Deduction joining the consequents of two premises. A deduction associated with pm3.2im . (Contributed by NM, 28-Dec-1992)

	Ref	Expression
Hypotheses	jc.1	|- ( ph -> ps )
	jc.2	|- ( ph -> ch )
Assertion	jc	|- ( ph -> -. ( ps -> -. ch ) )

Proof

Step	Hyp	Ref	Expression
1		jc.1	|- ( ph -> ps )
2		jc.2	|- ( ph -> ch )
3		pm3.2im	|- ( ps -> ( ch -> -. ( ps -> -. ch ) ) )
4	1 2 3	sylc	|- ( ph -> -. ( ps -> -. ch ) )