Metamath Proof Explorer


Theorem hbaev

Description: All variables are effectively bound in an identical variable specifier. Version of hbae with a disjoint variable condition, requiring fewer axioms. Instance of aev2 . (Contributed by NM, 13-May-1993) (Revised by Wolf Lammen, 22-Mar-2021)

Ref Expression
Assertion hbaev
|- ( A. x x = y -> A. z A. x x = y )

Proof

Step Hyp Ref Expression
1 aev2
 |-  ( A. x x = y -> A. z A. x x = y )