Theorem ordelon 4504

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 4502	. 2 |- ( ( Ord A /\ B e. A ) -> Ord B )
2		elong 4494	. . 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 2203   Ord word 4483   Oncon0 4484

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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2214

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-ral 2525  df-rex 2526  df-v 2815  df-in 3217  df-ss 3224  df-uni 3915  df-tr 4209  df-iord 4487  df-on 4489

This theorem is referenced by:  onelon  4505  ordsson  4614  ordpwsucss  4689  tfr1onlemsucfn  6571  tfr1onlemsucaccv  6572  tfr1onlembfn  6575  tfr1onlemubacc  6577  tfr1onlemaccex  6579  tfrcllemsucfn  6584  tfrcllemsucaccv  6585  tfrcllembfn  6588  tfrcllemubacc  6590  tfrcllemaccex  6592  tfrcl  6595