MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  ab0orvALT Structured version   Visualization version   GIF version

Theorem ab0orvALT 4364
Description: Alternate proof of ab0orv 4363, shorter but using more axioms. (Contributed by Mario Carneiro, 29-Aug-2013.) (Revised by BJ, 22-Mar-2020.) (Proof modification is discouraged.) (New usage is discouraged.)
Assertion
Ref Expression
ab0orvALT ({𝑥𝜑} = V ∨ {𝑥𝜑} = ∅)
Distinct variable group:   𝜑,𝑥

Proof of Theorem ab0orvALT
StepHypRef Expression
1 nfv 1914 . 2 𝑥𝜑
2 dfnf5 4362 . 2 (Ⅎ𝑥𝜑 ↔ ({𝑥𝜑} = V ∨ {𝑥𝜑} = ∅))
31, 2mpbi 230 1 ({𝑥𝜑} = V ∨ {𝑥𝜑} = ∅)
Colors of variables: wff setvar class
Syntax hints:  wo 847   = wceq 1540  wnf 1783  {cab 2714  Vcvv 3464  c0 4313
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2708
This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-clab 2715  df-cleq 2728  df-v 3466  df-dif 3934  df-nul 4314
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator