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Axiom ax-6 1729
Description: Axiom of Quantified Negation. Axiom C5-2 of [Monk2] p. 113. This axiom scheme is logically redundant (see ax6w 1717) but is used as an auxiliary axiom to achieve metalogical completeness. (Contributed by NM, 5-Aug-1993.)
Assertion
Ref Expression
ax-6 xφx ¬ xφ)

Detailed syntax breakdown of Axiom ax-6
StepHypRef Expression
1 wph . . . 4 wff φ
2 vx . . . 4 setvar x
31, 2wal 1540 . . 3 wff xφ
43wn 3 . 2 wff ¬ xφ
54, 2wal 1540 . 2 wff x ¬ xφ
64, 5wi 4 1 wff xφx ¬ xφ)
Colors of variables: wff setvar class
This axiom is referenced by:  hbn1  1730  ax6o  1750
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