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Theorem ordsucg 4502
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 4500 . 2  |-  ( Ord 
A  ->  Ord  suc  A
)
2 sucidg 4417 . . 3  |-  ( A  e.  _V  ->  A  e.  suc  A )
3 ordelord 4382 . . . 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 2148   _Vcvv 2738   Ord word 4363   suc csuc 4366
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 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159
This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-nf 1461  df-sb 1763  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460  df-rex 2461  df-v 2740  df-un 3134  df-in 3136  df-ss 3143  df-sn 3599  df-uni 3811  df-tr 4103  df-iord 4367  df-suc 4372
This theorem is referenced by:  onsucb  4503
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