Theorem relss 4747

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 3187	. 2 |- ( A C_ B -> ( B C_ ( _V X. _V ) -> A C_ ( _V X. _V ) ) )
2		df-rel 4667	. 2 |- ( Rel B <-> B C_ ( _V X. _V ) )
3		df-rel 4667	. 2 |- ( Rel A <-> A C_ ( _V X. _V ) )
4	1, 2, 3	3imtr4g 205	1 |- ( A C_ B -> ( Rel B -> Rel A ) )

Syntax hints:   -> wi 4   _Vcvv 2760   C_ wss 3154   X. cxp 4658   Rel wrel 4665

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-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-11 1517  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175

This theorem depends on definitions:  df-bi 117  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-in 3160  df-ss 3167  df-rel 4667

This theorem is referenced by:  relin1  4778  relin2  4779  reldif  4780  relres  4971  iss  4989  cnvdif  5073  funss  5274  funssres  5297  fliftcnv  5839  fliftfun  5840  reltpos  6305  tpostpos  6319  swoer  6617  erinxp  6665  ltrel  8083  lerel  8085  txdis1cn  14457  xmeter  14615  lgsquadlem1  15234  lgsquadlem2  15235