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Axiom ax-6o 980
Description: Axiom of Quantified Negation. This axiom is used to manipulate negated quantifiers. One of the 4 axioms of pure predicate calculus. Equivalent to axiom scheme C7' in [Megill] p. 448 (p. 16 of the preprint). An alternate axiomatization could use ax467 1025 in place of ax-4 975, ax-6o 980, and ax-7 964.

This axiom is redundant, as shown by theorem ax6o 979.

Assertion
Ref Expression
ax-6o |- (-. A.x -. A.xph -> ph)

Detailed syntax breakdown of Axiom ax-6o
StepHypRef Expression
1 wph . . . . . 6 wff ph
2 vx . . . . . 6 set x
31, 2wal 956 . . . . 5 wff A.xph
43wn 2 . . . 4 wff -. A.xph
54, 2wal 956 . . 3 wff A.x -. A.xph
65wn 2 . 2 wff -. A.x -. A.xph
76, 1wi 3 1 wff (-. A.x -. A.xph -> ph)
Colors of variables: wff set class
This axiom is referenced by:  ax6 981  a6e 992  hbnt 1004  ax46 1019  ax67 1022  ax467 1025  modal-b 1030  equid 1128
Copyright terms: Public domain