Theorem relss 4691

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 3149	. 2 |- ( A C_ B -> ( B C_ ( _V X. _V ) -> A C_ ( _V X. _V ) ) )
2		df-rel 4611	. 2 |- ( Rel B <-> B C_ ( _V X. _V ) )
3		df-rel 4611	. 2 |- ( Rel A <-> A C_ ( _V X. _V ) )
4	1, 2, 3	3imtr4g 204	1 |- ( A C_ B -> ( Rel B -> Rel A ) )

Syntax hints:   -> wi 4   _Vcvv 2726   C_ wss 3116   X. cxp 4602   Rel wrel 4609

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-11 1494  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147

This theorem depends on definitions:  df-bi 116  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-in 3122  df-ss 3129  df-rel 4611

This theorem is referenced by:  relin1  4722  relin2  4723  reldif  4724  relres  4912  iss  4930  cnvdif  5010  funss  5207  funssres  5230  fliftcnv  5763  fliftfun  5764  reltpos  6218  tpostpos  6232  swoer  6529  erinxp  6575  ltrel  7960  lerel  7962  txdis1cn  12918  xmeter  13076