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

Theorem ordsucg 4568
Description: The successor of an ordinal class is ordinal. (Contributed by Jim Kingdon, 20-Nov-2018.)
Assertion
Ref Expression
ordsucg  |-  ( A  e.  _V  ->  ( Ord  A  <->  Ord  suc  A )
)

Proof of Theorem ordsucg
StepHypRef Expression
1 ordsucim 4566 . 2  |-  ( Ord 
A  ->  Ord  suc  A
)
2 sucidg 4481 . . 3  |-  ( A  e.  _V  ->  A  e.  suc  A )
3 ordelord 4446 . . . 4  |-  ( ( Ord  suc  A  /\  A  e.  suc  A )  ->  Ord  A )
43ex 115 . . 3  |-  ( Ord 
suc  A  ->  ( A  e.  suc  A  ->  Ord  A ) )
52, 4syl5com 29 . 2  |-  ( A  e.  _V  ->  ( Ord  suc  A  ->  Ord  A ) )
61, 5impbid2 143 1  |-  ( A  e.  _V  ->  ( Ord  A  <->  Ord  suc  A )
)
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 105    e. wcel 2178   _Vcvv 2776   Ord word 4427   suc csuc 4430
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 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2189
This theorem depends on definitions:  df-bi 117  df-3an 983  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2194  df-cleq 2200  df-clel 2203  df-nfc 2339  df-ral 2491  df-rex 2492  df-v 2778  df-un 3178  df-in 3180  df-ss 3187  df-sn 3649  df-uni 3865  df-tr 4159  df-iord 4431  df-suc 4436
This theorem is referenced by:  onsucb  4569
  Copyright terms: Public domain W3C validator