Theorem resiexg 4992

Description: The existence of a restricted identity function, proved without using the Axiom of Replacement. (Contributed by NM, 13-Jan-2007.)

Assertion

Ref	Expression
resiexg	|- ( A e. V -> ( _I |` A ) e. _V )

Proof of Theorem resiexg

Dummy variables x y are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		relres 4975	. . 3 |- Rel ( _I |` A )
2		simpr 110	. . . . 5 |- ( ( x = y /\ x e. A ) -> x e. A )
3		eleq1 2259	. . . . . 6 |- ( x = y -> ( x e. A <-> y e. A ) )
4	3	biimpa 296	. . . . 5 |- ( ( x = y /\ x e. A ) -> y e. A )
5	2, 4	jca 306	. . . 4 |- ( ( x = y /\ x e. A ) -> ( x e. A /\ y e. A ) )
6		vex 2766	. . . . . 6 |- y e. _V
7	6	opelres 4952	. . . . 5 |- ( <. x , y >. e. ( _I |` A ) <-> ( <. x , y >. e. _I /\ x e. A ) )
8		df-br 4035	. . . . . . 7 |- ( x _I y <-> <. x , y >. e. _I )
9	6	ideq 4819	. . . . . . 7 |- ( x _I y <-> x = y )
10	8, 9	bitr3i 186	. . . . . 6 |- ( <. x , y >. e. _I <-> x = y )
11	10	anbi1i 458	. . . . 5 |- ( ( <. x , y >. e. _I /\ x e. A ) <-> ( x = y /\ x e. A ) )
12	7, 11	bitri 184	. . . 4 |- ( <. x , y >. e. ( _I |` A ) <-> ( x = y /\ x e. A ) )
13		opelxp 4694	. . . 4 |- ( <. x , y >. e. ( A X. A ) <-> ( x e. A /\ y e. A ) )
14	5, 12, 13	3imtr4i 201	. . 3 |- ( <. x , y >. e. ( _I |` A ) -> <. x , y >. e. ( A X. A ) )
15	1, 14	relssi 4755	. 2 |- ( _I |` A ) C_ ( A X. A )
16		xpexg 4778	. . 3 |- ( ( A e. V /\ A e. V ) -> ( A X. A ) e. _V )
17	16	anidms 397	. 2 |- ( A e. V -> ( A X. A ) e. _V )
18		ssexg 4173	. 2 |- ( ( ( _I |` A ) C_ ( A X. A ) /\ ( A X. A ) e. _V ) -> ( _I |` A ) e. _V )
19	15, 17, 18	sylancr 414	1 |- ( A e. V -> ( _I |` A ) e. _V )

Syntax hints:   -> wi 4   /\ wa 104   e. wcel 2167   _Vcvv 2763   C_ wss 3157   <.cop 3626   class class class wbr 4034   _I cid 4324   X. cxp 4662   |` cres 4666

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 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-13 2169  ax-14 2170  ax-ext 2178  ax-sep 4152  ax-pow 4208  ax-pr 4243  ax-un 4469

This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-nf 1475  df-sb 1777  df-eu 2048  df-mo 2049  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-ral 2480  df-rex 2481  df-v 2765  df-un 3161  df-in 3163  df-ss 3170  df-pw 3608  df-sn 3629  df-pr 3630  df-op 3632  df-uni 3841  df-br 4035  df-opab 4096  df-id 4329  df-xp 4670  df-rel 4671  df-res 4676

This theorem is referenced by:  ordiso  7111  omct  7192  ctssexmid  7225  ssomct  12687  ndxarg  12726  subctctexmid  15731