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Theorem ralnex 2494
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 2489 . 2 (∀𝑥𝐴 ¬ 𝜑 ↔ ∀𝑥(𝑥𝐴 → ¬ 𝜑))
2 alinexa 1626 . . 3 (∀𝑥(𝑥𝐴 → ¬ 𝜑) ↔ ¬ ∃𝑥(𝑥𝐴𝜑))
3 df-rex 2490 . . 3 (∃𝑥𝐴 𝜑 ↔ ∃𝑥(𝑥𝐴𝜑))
42, 3xchbinxr 685 . 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 1371  wex 1515  wcel 2176  wral 2484  wrex 2485
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 615  ax-in2 616  ax-5 1470  ax-gen 1472  ax-ie2 1517
This theorem depends on definitions:  df-bi 117  df-tru 1376  df-fal 1379  df-ral 2489  df-rex 2490
This theorem is referenced by:  nnral  2496  rexalim  2499  ralinexa  2533  nrex  2598  nrexdv  2599  ralnex2  2645  r19.30dc  2653  uni0b  3875  iindif2m  3995  f0rn0  5470  supmoti  7095  fodjuomnilemdc  7246  ismkvnex  7257  nninfwlpoimlemginf  7278  suprnubex  9026  icc0r  10048  ioo0  10402  ico0  10404  ioc0  10405  prmind2  12442  sqrt2irr  12484  nconstwlpolem  16004
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