Theorem conimpfalt

Description: Assuming a, not b, and a implies b, there exists a proof that a is false.) (Contributed by Jarvin Udandy, 29-Aug-2016)

	Ref	Expression
Hypotheses	conimpfalt.1	|- ph
	conimpfalt.2	|- -. ps
	conimpfalt.3	|- ( ph -> ps )
Assertion	conimpfalt	|- ( ph <-> F. )

Proof

Step	Hyp	Ref	Expression
1		conimpfalt.1	|- ph
2		conimpfalt.2	|- -. ps
3		conimpfalt.3	|- ( ph -> ps )
4	3 2	aibnbaif	|- ( ph <-> F. )