Theorem relss 4427

Description: Subclass theorem for relation predicate. Theorem 2 of [Suppes] p. 58. (Contributed by NM, 15-Aug-1994.)

Assertion

Ref	Expression
relss	|- ( A C_ B -> ( Rel B -> Rel A ) )

Proof of Theorem relss

Step	Hyp	Ref	Expression
1		sstr2 2952	. 2 |- ( A C_ B -> ( B C_ ( _V X. _V ) -> A C_ ( _V X. _V ) ) )
2		df-rel 4352	. 2 |- ( Rel B <-> B C_ ( _V X. _V ) )
3		df-rel 4352	. 2 |- ( Rel A <-> A C_ ( _V X. _V ) )
4	1, 2, 3	3imtr4g 194	1 |- ( A C_ B -> ( Rel B -> Rel A ) )

Syntax hints:   -> wi 4   _Vcvv 2557   C_ wss 2917   X. cxp 4343   Rel wrel 4350

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-11 1397  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-in 2924  df-ss 2931  df-rel 4352

This theorem is referenced by:  relin1  4455  relin2  4456  reldif  4457  relres  4639  iss  4654  cnvdif  4730  funss  4920  funssres  4942  fliftcnv  5435  fliftfun  5436  reltpos  5865  tpostpos  5879  swoer  6134  erinxp  6180  ltrel  7081  lerel  7083