ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  0cnALT Unicode version

Theorem 0cnALT 8216
Description: Alternate proof of 0cn 8018. (Contributed by NM, 19-Feb-2005.) (Revised by Mario Carneiro, 27-May-2016.) (Proof modification is discouraged.) (New usage is discouraged.)
Assertion
Ref Expression
0cnALT  |-  0  e.  CC

Proof of Theorem 0cnALT
StepHypRef Expression
1 ax-icn 7974 . . 3  |-  _i  e.  CC
2 cnegex 8204 . . 3  |-  ( _i  e.  CC  ->  E. x  e.  CC  ( _i  +  x )  =  0 )
31, 2ax-mp 5 . 2  |-  E. x  e.  CC  ( _i  +  x )  =  0
4 addcl 8004 . . . . 5  |-  ( ( _i  e.  CC  /\  x  e.  CC )  ->  ( _i  +  x
)  e.  CC )
51, 4mpan 424 . . . 4  |-  ( x  e.  CC  ->  (
_i  +  x )  e.  CC )
6 eleq1 2259 . . . 4  |-  ( ( _i  +  x )  =  0  ->  (
( _i  +  x
)  e.  CC  <->  0  e.  CC ) )
75, 6syl5ibcom 155 . . 3  |-  ( x  e.  CC  ->  (
( _i  +  x
)  =  0  -> 
0  e.  CC ) )
87rexlimiv 2608 . 2  |-  ( E. x  e.  CC  (
_i  +  x )  =  0  ->  0  e.  CC )
93, 8ax-mp 5 1  |-  0  e.  CC
Colors of variables: wff set class
Syntax hints:    = wceq 1364    e. wcel 2167   E.wrex 2476  (class class class)co 5922   CCcc 7877   0cc0 7879   _ici 7881    + caddc 7882
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-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178  ax-resscn 7971  ax-1cn 7972  ax-icn 7974  ax-addcl 7975  ax-addrcl 7976  ax-mulcl 7977  ax-addcom 7979  ax-addass 7981  ax-distr 7983  ax-i2m1 7984  ax-0id 7987  ax-rnegex 7988  ax-cnre 7990
This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ral 2480  df-rex 2481  df-v 2765  df-un 3161  df-in 3163  df-ss 3170  df-sn 3628  df-pr 3629  df-op 3631  df-uni 3840  df-br 4034  df-iota 5219  df-fv 5266  df-ov 5925
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator