Axiom ax-9d2 2298

Description: Distinct variable version of ax9 1949, distinct variables case. (Contributed by Mario Carneiro, 14-Aug-2015.)

Assertion

Ref	Expression
ax-9d2	|- -. A.x -. x = y

Distinct variable group:   x,y

Detailed syntax breakdown of Axiom ax-9d2

Step	Hyp	Ref	Expression
1		vx	. . . . 5 setvar x
2		vy	. . . . 5 setvar y
3	1, 2	weq 1643	. . . 4 wff x = y
4	3	wn 3	. . 3 wff -. x = y
5	4, 1	wal 1540	. 2 wff A.x -. x = y
6	5	wn 3	1 wff -. A.x -. x = y

This axiom is referenced by: (None)