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Theorem 2ax17 1640
Description: Quantification of two variables over a formula in which they do not occur. (Contributed by Alan Sare, 12-Apr-2011.)
Ref Expression
2ax17 (φxyφ)
Distinct variable groups:   φ,x   φ,y

Proof of Theorem 2ax17
StepHypRef Expression
1 id 19 . 2 (φφ)
21alrimivv 1632 1 (φxyφ)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wal 1540
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 8  ax-gen 1546  ax-5 1557  ax-17 1616
This theorem is referenced by: (None)
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