Theorem elpw 3658

Description: Membership in a power class. Theorem 86 of [Suppes] p. 47. (Contributed by NM, 31-Dec-1993.)

Hypothesis

Ref	Expression
elpw.1	|- A e. _V

Assertion

Ref	Expression
elpw	|- ( A e. ~P B <-> A C_ B )

Proof of Theorem elpw

Dummy variable x is distinct from all other variables.

Step	Hyp	Ref	Expression
1		elpw.1	. 2 |- A e. _V
2		sseq1 3250	. 2 |- ( x = A -> ( x C_ B <-> A C_ B ) )
3		df-pw 3654	. 2 |- ~P B = { x | x C_ B }
4	1, 2, 3	elab2 2954	1 |- ( A e. ~P B <-> A C_ B )

Syntax hints:   <-> wb 105   e. wcel 2202   _Vcvv 2802   C_ wss 3200   ~Pcpw 3652

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 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-tru 1400  df-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-v 2804  df-in 3206  df-ss 3213  df-pw 3654

This theorem is referenced by:  velpw  3659  elpwg  3660  prsspw  3848  pwprss  3889  pwtpss  3890  pwv  3892  sspwuni  4055  iinpw  4061  iunpwss  4062  0elpw  4254  pwuni  4282  snelpw  4304  sspwb  4308  ssextss  4312  pwin  4379  pwunss  4380  iunpw  4577  xpsspw  4838  ssenen  7036  pw1ne3  7447  3nsssucpw1  7453  ioof  10205  tgdom  14795  distop  14808  epttop  14813  resttopon  14894  txuni2  14979  umgrbien  15960  umgredg  15995