19.25

Theorem.

Arguments:

(sv), (sv), (pr), (pr),

Assertions:

(()())

Proof:

Hyp	Ref	Line	Expr
	bexim	1	(()())
1	bi>	2	(()())
2	im.bldal	3	(()())
	im.bldext	4	(()())
3, 4	syl	5	(()())