Theorem hblemg

Description: Change the free variable of a hypothesis builder. Usage of this theorem is discouraged because it depends on ax-13 . See hblem for a version with more disjoint variable conditions, but not requiring ax-13 . (Contributed by NM, 21-Jun-1993) (Revised by Andrew Salmon, 11-Jul-2011) (New usage is discouraged.)

	Ref	Expression
Hypothesis	hblemg.1	$$⊢y\in A\to \forall xy\in A$$
Assertion	hblemg	$$⊢z\in A\to \forall xz\in A$$

Proof

Step	Hyp	Ref	Expression
1		hblemg.1	$$⊢y\in A\to \forall xy\in A$$
2	1	hbsb	$$⊢\left[z/y\right]y\in A\to \forall x\left[z/y\right]y\in A$$
3		clelsb3	$$⊢\left[z/y\right]y\in A\leftrightarrow z\in A$$
4	3	albii	$$⊢\forall x\left[z/y\right]y\in A\leftrightarrow \forall xz\in A$$
5	2 3 4	3imtr3i	$$⊢z\in A\to \forall xz\in A$$