ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  ax-9 Unicode version

Theorem ax-9 1283
Description: Derive ax-9 1283 from ax-i9 1282, the modified version for intuitionistic logic. Although ax-9 1283 does hold intuistionistically, in intuitionistic logic it is weaker than ax-i9 1282. (Contributed by NM, 3-Feb-2015.)
Assertion
Ref Expression
ax-9

Proof of Theorem ax-9
StepHypRef Expression
1 ax-i9 1282 . . 3
21notnoti 552 . 2
3 alnex 1259 . 2
42, 3mtbir 574 1
Colors of variables: wff set class
Syntax hints:   wn 3  wal 1214  wex 1253   wceq 1262
This theorem is referenced by:  equidqe  1284  equidqeOLD  1285  ax4  1808
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 97  ax-ia2 98  ax-ia3 99  ax-in1 526  ax-in2 527  ax-5 1215  ax-gen 1218  ax-ie2 1255  ax-i9 1282
This theorem depends on definitions:  df-bi 108  df-tru 1192  df-fal 1193
  Copyright terms: Public domain W3C validator