Theorem biimpd

Description: Deduce an implication from a logical equivalence. Deduction associated with biimp and biimpi . (Contributed by NM, 11-Jan-1993)

	Ref	Expression
Hypothesis	biimpd.1	|- ( ph -> ( ps <-> ch ) )
Assertion	biimpd	|- ( ph -> ( ps -> ch ) )

Proof

Step	Hyp	Ref	Expression
1		biimpd.1	|- ( ph -> ( ps <-> ch ) )
2		biimp	|- ( ( ps <-> ch ) -> ( ps -> ch ) )
3	1 2	syl	|- ( ph -> ( ps -> ch ) )