Theorem ordelon 4474

Description: An element of an ordinal class is an ordinal number. (Contributed by NM, 26-Oct-2003.)

Assertion

Ref	Expression
ordelon	|- ( ( Ord A /\ B e. A ) -> B e. On )

Proof of Theorem ordelon

Step	Hyp	Ref	Expression
1		ordelord 4472	. 2 |- ( ( Ord A /\ B e. A ) -> Ord B )
2		elong 4464	. . 3 |- ( B e. A -> ( B e. On <-> Ord B ) )
3	2	adantl 277	. 2 |- ( ( Ord A /\ B e. A ) -> ( B e. On <-> Ord B ) )
4	1, 3	mpbird 167	1 |- ( ( Ord A /\ B e. A ) -> B e. On )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   e. wcel 2200   Ord word 4453   Oncon0 4454

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 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-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-rex 2514  df-v 2801  df-in 3203  df-ss 3210  df-uni 3889  df-tr 4183  df-iord 4457  df-on 4459

This theorem is referenced by:  onelon  4475  ordsson  4584  ordpwsucss  4659  tfr1onlemsucfn  6486  tfr1onlemsucaccv  6487  tfr1onlembfn  6490  tfr1onlemubacc  6492  tfr1onlemaccex  6494  tfrcllemsucfn  6499  tfrcllemsucaccv  6500  tfrcllembfn  6503  tfrcllemubacc  6505  tfrcllemaccex  6507  tfrcl  6510