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Theorem nexr 1627
Description: Inference from 19.8a 1527. (Contributed by Jeff Hankins, 26-Jul-2009.)
Hypothesis
Ref Expression
nexr.1 ¬ ∃𝑥𝜑
Assertion
Ref Expression
nexr ¬ 𝜑

Proof of Theorem nexr
StepHypRef Expression
1 nexr.1 . 2 ¬ ∃𝑥𝜑
2 19.8a 1527 . 2 (𝜑 → ∃𝑥𝜑)
31, 2mto 623 1 ¬ 𝜑
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wex 1426
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-in1 579  ax-in2 580  ax-gen 1383  ax-ie1 1427  ax-ie2 1428  ax-4 1445
This theorem depends on definitions:  df-bi 115
This theorem is referenced by: (None)
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