Theorem relss 4864

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 3255	. 2 |- ( A C_ B -> ( B C_ ( _V X. _V ) -> A C_ ( _V X. _V ) ) )
2		df-rel 4783	. 2 |- ( Rel B <-> B C_ ( _V X. _V ) )
3		df-rel 4783	. 2 |- ( Rel A <-> A C_ ( _V X. _V ) )
4	1, 2, 3	3imtr4g 205	1 |- ( A C_ B -> ( Rel B -> Rel A ) )

This proof depends on syntax axioms:   -> wi 4   _Vcvv 2821   C_ wss 3220   X. cxp 4774   Rel wrel 4781

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-11 1559  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220

This proof depends on definitions:  df-bi 117  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-in 3226  df-ss 3233  df-rel 4783

This theorem is used by:  relin1  4897  relin2  4898  reldif  4899  relres  5093  iss  5112  cnvdif  5197  funss  5399  funssres  5423  fliftcnv  6004  fliftfun  6005  reltpos  6525  tpostpos  6539  swoer  6839  erinxp  6887  ltrel  8393  lerel  8395  txdis1cn  15504  xmeter  15662  lgsquadlem1  16401  lgsquadlem2  16402