MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  nfan1 Structured version   Visualization version   GIF version

Theorem nfan1 2237
Description: A closed form of nfan 1921. (Contributed by Mario Carneiro, 3-Oct-2016.) df-nf 1806 changed. (Revised by Wolf Lammen, 18-Sep-2021.) (Proof shortened by Wolf Lammen, 7-Jul-2022.)
Hypotheses
Ref Expression
nfim1.1 𝑥𝜑
nfim1.2 (𝜑 → Ⅎ𝑥𝜓)
Assertion
Ref Expression
nfan1 𝑥(𝜑𝜓)

Proof of Theorem nfan1
StepHypRef Expression
1 df-an 400 . 2 ((𝜑𝜓) ↔ ¬ (𝜑 → ¬ 𝜓))
2 nfim1.1 . . . 4 𝑥𝜑
3 nfim1.2 . . . . 5 (𝜑 → Ⅎ𝑥𝜓)
43nfnd 1880 . . . 4 (𝜑 → Ⅎ𝑥 ¬ 𝜓)
52, 4nfim1 2236 . . 3 𝑥(𝜑 → ¬ 𝜓)
65nfn 1879 . 2 𝑥 ¬ (𝜑 → ¬ 𝜓)
71, 6nfxfr 1875 1 𝑥(𝜑𝜓)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 399  wnf 1805
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1817  ax-4 1831  ax-5 1932  ax-6 1989  ax-7 2030  ax-12 2214
This theorem depends on definitions:  df-bi 209  df-an 400  df-or 859  df-ex 1802  df-nf 1806
This theorem is referenced by:  sb4b  2508  ralcom2  3366  sbcralt  3827  sbcrext  3828  csbiebt  3883  riota5f  7383  axrepndlem1  10552  axrepndlem2  10553  axunnd  10556  axpowndlem2  10558  axpowndlem3  10559  axpowndlem4  10560  axregndlem2  10563  axinfndlem1  10565  axinfnd  10566  axacndlem4  10570  axacndlem5  10571  axacnd  10572  fproddivf  16019  nfan1c  35370  axtcond  36843  mh-setindnd  36902  wl-sbcom2d-lem1  38067  wl-mo2df  38078  wl-eudf  38080  wl-mo3t  38084
  Copyright terms: Public domain W3C validator