Theorem e2bir

Description: Right biconditional form of e2 . syl6ibr is e2bir without virtual deductions. (Contributed by Alan Sare, 29-Apr-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypotheses	e2bir.1	|- (. ph ,. ps ->. ch ).
	e2bir.2	|- ( th <-> ch )
Assertion	e2bir	|- (. ph ,. ps ->. th ).

Proof

Step	Hyp	Ref	Expression
1		e2bir.1	|- (. ph ,. ps ->. ch ).
2		e2bir.2	|- ( th <-> ch )
3	2	biimpri	|- ( ch -> th )
4	1 3	e2	|- (. ph ,. ps ->. th ).