Theorem abid2 2352

Description: A simplification of class abstraction. Theorem 5.2 of [Quine] p. 35. (Contributed by NM, 26-Dec-1993.)

Assertion

Ref	Expression
abid2	|- { x | x e. A } = A

Distinct variable group:   x, A

Proof of Theorem abid2

Step	Hyp	Ref	Expression
1		biid 171	. . 3 |- ( x e. A <-> x e. A )
2	1	abbi2i 2346	. 2 |- A = { x | x e. A }
3	2	eqcomi 2235	1 |- { x | x e. A } = A

Syntax hints:   = wceq 1397   e. wcel 2202   {cab 2217

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 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-11 1554  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-nf 1509  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227

This theorem is referenced by:  csbid  3135  abss  3296  ssab  3297  abssi  3302  notab  3477  inrab2  3480  dfrab2  3482  dfrab3  3483  notrab  3484  eusn  3745  dfopg  3860  iunid  4026  csbexga  4217  imai  5092  dffv4g  5636  frec0g  6562  dfixp  6868  euen1b  6976  modom2  6994  acfun  7421  ccfunen  7482