Theorem restperf 20988

Description: Perfection of a subspace. Note that the term "perfect set" is reserved for closed sets which are perfect in the subspace topology. (Contributed by Mario Carneiro, 25-Dec-2016.)

Hypotheses

Ref	Expression
restcls.1	|- X = U. J
restcls.2	|- K = ( J ↾t Y )

Assertion

Ref	Expression
restperf	|- ( ( J e. Top /\ Y C_ X ) -> ( K e. Perf <-> Y C_ ( ( limPt ` J ) ` Y ) ) )

Proof of Theorem restperf

Step	Hyp	Ref	Expression
1		restcls.2	. . . . 5 |- K = ( J ↾t Y )
2		restcls.1	. . . . . . 7 |- X = U. J
3	2	toptopon 20722	. . . . . 6 |- ( J e. Top <-> J e. (TopOn ` X ) )
4		resttopon 20965	. . . . . 6 |- ( ( J e. (TopOn ` X ) /\ Y C_ X ) -> ( J ↾t Y ) e. (TopOn ` Y ) )
5	3, 4	sylanb 489	. . . . 5 |- ( ( J e. Top /\ Y C_ X ) -> ( J ↾t Y ) e. (TopOn ` Y ) )
6	1, 5	syl5eqel 2705	. . . 4 |- ( ( J e. Top /\ Y C_ X ) -> K e. (TopOn ` Y ) )
7		topontop 20718	. . . 4 |- ( K e. (TopOn ` Y ) -> K e. Top )
8	6, 7	syl 17	. . 3 |- ( ( J e. Top /\ Y C_ X ) -> K e. Top )
9		eqid 2622	. . . . 5 |- U. K = U. K
10	9	isperf 20955	. . . 4 |- ( K e. Perf <-> ( K e. Top /\ ( ( limPt ` K ) ` U. K ) = U. K ) )
11	10	baib 944	. . 3 |- ( K e. Top -> ( K e. Perf <-> ( ( limPt ` K ) ` U. K ) = U. K ) )
12	8, 11	syl 17	. 2 |- ( ( J e. Top /\ Y C_ X ) -> ( K e. Perf <-> ( ( limPt ` K ) ` U. K ) = U. K ) )
13		sseqin2 3817	. . 3 |- ( Y C_ ( ( limPt ` J ) ` Y ) <-> ( ( ( limPt ` J ) ` Y ) i^i Y ) = Y )
14		ssid 3624	. . . . . 6 |- Y C_ Y
15	2, 1	restlp 20987	. . . . . 6 |- ( ( J e. Top /\ Y C_ X /\ Y C_ Y ) -> ( ( limPt ` K ) ` Y ) = ( ( ( limPt ` J ) ` Y ) i^i Y ) )
16	14, 15	mp3an3 1413	. . . . 5 |- ( ( J e. Top /\ Y C_ X ) -> ( ( limPt ` K ) ` Y ) = ( ( ( limPt ` J ) ` Y ) i^i Y ) )
17		toponuni 20719	. . . . . . 7 |- ( K e. (TopOn ` Y ) -> Y = U. K )
18	6, 17	syl 17	. . . . . 6 |- ( ( J e. Top /\ Y C_ X ) -> Y = U. K )
19	18	fveq2d 6195	. . . . 5 |- ( ( J e. Top /\ Y C_ X ) -> ( ( limPt ` K ) ` Y ) = ( ( limPt ` K ) ` U. K ) )
20	16, 19	eqtr3d 2658	. . . 4 |- ( ( J e. Top /\ Y C_ X ) -> ( ( ( limPt ` J ) ` Y ) i^i Y ) = ( ( limPt ` K ) ` U. K ) )
21	20, 18	eqeq12d 2637	. . 3 |- ( ( J e. Top /\ Y C_ X ) -> ( ( ( ( limPt ` J ) ` Y ) i^i Y ) = Y <-> ( ( limPt ` K ) ` U. K ) = U. K ) )
22	13, 21	syl5bb 272	. 2 |- ( ( J e. Top /\ Y C_ X ) -> ( Y C_ ( ( limPt ` J ) ` Y ) <-> ( ( limPt ` K ) ` U. K ) = U. K ) )
23	12, 22	bitr4d 271	1 |- ( ( J e. Top /\ Y C_ X ) -> ( K e. Perf <-> Y C_ ( ( limPt ` J ) ` Y ) ) )

Syntax hints:   -> wi 4   <-> wb 196   /\ wa 384   = wceq 1483   e. wcel 1990   i^i cin 3573   C_ wss 3574   U.cuni 4436   ` cfv 5888  (class class class)co 6650   ↾_t crest 16081   Topctop 20698  TopOnctopon 20715   limPtclp 20938  Perfcperf 20939

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-rep 4771  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-ral 2917  df-rex 2918  df-reu 2919  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-pss 3590  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-tp 4182  df-op 4184  df-uni 4437  df-int 4476  df-iun 4522  df-iin 4523  df-br 4654  df-opab 4713  df-mpt 4730  df-tr 4753  df-id 5024  df-eprel 5029  df-po 5035  df-so 5036  df-fr 5073  df-we 5075  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-pred 5680  df-ord 5726  df-on 5727  df-lim 5728  df-suc 5729  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-om 7066  df-1st 7168  df-2nd 7169  df-wrecs 7407  df-recs 7468  df-rdg 7506  df-oadd 7564  df-er 7742  df-en 7956  df-fin 7959  df-fi 8317  df-rest 16083  df-topgen 16104  df-top 20699  df-topon 20716  df-bases 20750  df-cld 20823  df-cls 20825  df-lp 20940  df-perf 20941

This theorem is referenced by:  perfcls  21169  reperflem  22621  perfdvf  23667