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

Theorem ralnex 2518
Description: Relationship between restricted universal and existential quantifiers. (Contributed by NM, 21-Jan-1997.)
Assertion
Ref Expression
ralnex (∀𝑥𝐴 ¬ 𝜑 ↔ ¬ ∃𝑥𝐴 𝜑)

Proof of Theorem ralnex
StepHypRef Expression
1 df-ral 2513 . 2 (∀𝑥𝐴 ¬ 𝜑 ↔ ∀𝑥(𝑥𝐴 → ¬ 𝜑))
2 alinexa 1649 . . 3 (∀𝑥(𝑥𝐴 → ¬ 𝜑) ↔ ¬ ∃𝑥(𝑥𝐴𝜑))
3 df-rex 2514 . . 3 (∃𝑥𝐴 𝜑 ↔ ∃𝑥(𝑥𝐴𝜑))
42, 3xchbinxr 687 . 2 (∀𝑥(𝑥𝐴 → ¬ 𝜑) ↔ ¬ ∃𝑥𝐴 𝜑)
51, 4bitri 184 1 (∀𝑥𝐴 ¬ 𝜑 ↔ ¬ ∃𝑥𝐴 𝜑)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wb 105  wal 1393  wex 1538  wcel 2200  wral 2508  wrex 2509
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 617  ax-in2 618  ax-5 1493  ax-gen 1495  ax-ie2 1540
This theorem depends on definitions:  df-bi 117  df-tru 1398  df-fal 1401  df-ral 2513  df-rex 2514
This theorem is referenced by:  nnral  2520  rexalim  2523  ralinexa  2557  nrex  2622  nrexdv  2623  ralnex2  2670  r19.30dc  2678  uni0b  3912  iindif2m  4032  f0rn0  5519  supmoti  7156  fodjuomnilemdc  7307  ismkvnex  7318  nninfwlpoimlemginf  7339  suprnubex  9096  icc0r  10118  ioo0  10474  ico0  10476  ioc0  10477  prmind2  12637  sqrt2irr  12679  umgrnloop0  15911  nconstwlpolem  16392
  Copyright terms: Public domain W3C validator