Metamath Proof Explorer


Theorem dvelimv

Description: Similar to dvelim with first hypothesis replaced by a distinct variable condition. Usage of this theorem is discouraged because it depends on ax-13 . Check out dvelimhw for a version requiring fewer axioms. (Contributed by NM, 25-Jul-2015) (Proof shortened by Wolf Lammen, 30-Apr-2018) (New usage is discouraged.)

Ref Expression
Hypothesis dvelimv.1
|- ( z = y -> ( ph <-> ps ) )
Assertion dvelimv
|- ( -. A. x x = y -> ( ps -> A. x ps ) )

Proof

Step Hyp Ref Expression
1 dvelimv.1
 |-  ( z = y -> ( ph <-> ps ) )
2 ax-5
 |-  ( ph -> A. x ph )
3 2 1 dvelim
 |-  ( -. A. x x = y -> ( ps -> A. x ps ) )