ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  abn0r Unicode version

Theorem abn0r 3516
Description: Nonempty class abstraction. (Contributed by Jim Kingdon, 1-Aug-2018.)
Assertion
Ref Expression
abn0r  |-  ( E. x ph  ->  { x  |  ph }  =/=  (/) )

Proof of Theorem abn0r
StepHypRef Expression
1 abid 2217 . . 3  |-  ( x  e.  { x  | 
ph }  <->  ph )
21exbii 1651 . 2  |-  ( E. x  x  e.  {
x  |  ph }  <->  E. x ph )
3 nfab1 2374 . . 3  |-  F/_ x { x  |  ph }
43n0rf 3504 . 2  |-  ( E. x  x  e.  {
x  |  ph }  ->  { x  |  ph }  =/=  (/) )
52, 4sylbir 135 1  |-  ( E. x ph  ->  { x  |  ph }  =/=  (/) )
Colors of variables: wff set class
Syntax hints:    -> wi 4   E.wex 1538    e. wcel 2200   {cab 2215    =/= wne 2400   (/)c0 3491
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-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-ext 2211
This theorem depends on definitions:  df-bi 117  df-tru 1398  df-fal 1401  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ne 2401  df-v 2801  df-dif 3199  df-nul 3492
This theorem is referenced by:  rabn0r  3518
  Copyright terms: Public domain W3C validator