Theorem abid2 2291

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 170	. . 3 |- ( x e. A <-> x e. A )
2	1	abbi2i 2285	. 2 |- A = { x | x e. A }
3	2	eqcomi 2174	1 |- { x | x e. A } = A

Syntax hints:   = wceq 1348   e. wcel 2141   {cab 2156

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 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-11 1499  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166

This theorem is referenced by:  csbid  3057  abss  3216  ssab  3217  abssi  3222  notab  3397  inrab2  3400  dfrab2  3402  dfrab3  3403  notrab  3404  eusn  3657  dfopg  3763  iunid  3928  csbexga  4117  imai  4967  dffv4g  5493  frec0g  6376  dfixp  6678  euen1b  6781  acfun  7184  ccfunen  7226