ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  nrex GIF version

Theorem nrex 2411
Description: Inference adding restricted existential quantifier to negated wff. (Contributed by NM, 16-Oct-2003.)
Hypothesis
Ref Expression
nrex.1 (𝑥𝐴 → ¬ 𝜓)
Assertion
Ref Expression
nrex ¬ ∃𝑥𝐴 𝜓

Proof of Theorem nrex
StepHypRef Expression
1 nrex.1 . . 3 (𝑥𝐴 → ¬ 𝜓)
21rgen 2374 . 2 𝑥𝐴 ¬ 𝜓
3 ralnex 2316 . 2 (∀𝑥𝐴 ¬ 𝜓 ↔ ¬ ∃𝑥𝐴 𝜓)
42, 3mpbi 133 1 ¬ ∃𝑥𝐴 𝜓
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wcel 1393  wral 2306  wrex 2307
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 544  ax-in2 545  ax-5 1336  ax-gen 1338  ax-ie2 1383
This theorem depends on definitions:  df-bi 110  df-tru 1246  df-fal 1249  df-ral 2311  df-rex 2312
This theorem is referenced by:  rex0  3238  iun0  3713  frec0g  5983  nominpos  8162  sqrt2irr  9878
  Copyright terms: Public domain W3C validator