Theorem rabss2 3253

Description: Subclass law for restricted abstraction. (Contributed by NM, 18-Dec-2004.) (Proof shortened by Andrew Salmon, 26-Jun-2011.)

Assertion

Ref	Expression
rabss2	|- ( A C_ B -> { x e. A | ph } C_ { x e. B | ph } )

Distinct variable groups:   x, A   x, B

Allowed substitution hint:   ph( x)

Proof of Theorem rabss2

Step	Hyp	Ref	Expression
1		pm3.45 597	. . . 4 |- ( ( x e. A -> x e. B ) -> ( ( x e. A /\ ph ) -> ( x e. B /\ ph ) ) )
2	1	alimi 1466	. . 3 |- ( A. x ( x e. A -> x e. B ) -> A. x ( ( x e. A /\ ph ) -> ( x e. B /\ ph ) ) )
3		dfss2 3159	. . 3 |- ( A C_ B <-> A. x ( x e. A -> x e. B ) )
4		ss2ab 3238	. . 3 |- ( { x | ( x e. A /\ ph ) } C_ { x | ( x e. B /\ ph ) } <-> A. x ( ( x e. A /\ ph ) -> ( x e. B /\ ph ) ) )
5	2, 3, 4	3imtr4i 201	. 2 |- ( A C_ B -> { x | ( x e. A /\ ph ) } C_ { x | ( x e. B /\ ph ) } )
6		df-rab 2477	. 2 |- { x e. A | ph } = { x | ( x e. A /\ ph ) }
7		df-rab 2477	. 2 |- { x e. B | ph } = { x | ( x e. B /\ ph ) }
8	5, 6, 7	3sstr4g 3213	1 |- ( A C_ B -> { x e. A | ph } C_ { x e. B | ph } )

Syntax hints:   -> wi 4   /\ wa 104   A.wal 1362   e. wcel 2160   {cab 2175   {crab 2472   C_ wss 3144

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 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2171

This theorem depends on definitions:  df-bi 117  df-nf 1472  df-sb 1774  df-clab 2176  df-cleq 2182  df-clel 2185  df-nfc 2321  df-rab 2477  df-in 3150  df-ss 3157

This theorem is referenced by:  sess2  4353  zsupssdc  11973  dvfgg  14554