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Theorem cldbnd 15410
Description: A set is closed iff it contains its boundary.
Hypothesis
Ref Expression
opnbnd.1 |- X = U.J
Assertion
Ref Expression
cldbnd |- ((J e. Top /\ A C_ X) -> (A e. (Clsd` J) <-> (((cls` J)` A) i^i ((cls` J)` (X \ A))) C_ A))

Proof of Theorem cldbnd
StepHypRef Expression
1 opnbnd.1 . . . . 5 |- X = U.J
21iscld3 8971 . . . 4 |- ((J e. Top /\ A C_ X) -> (A e. (Clsd` J) <-> ((cls` J)` A) = A))
3 eqimss 2665 . . . 4 |- (((cls` J)` A) = A -> ((cls`
J)` A) C_ A)
42, 3syl6bi 231 . . 3 |- ((J e. Top /\ A C_ X) -> (A e. (Clsd` J) -> ((cls` J)` A) C_ A))
5 ssinss1 2821 . . 3 |- (((cls` J)` A) C_ A -> (((cls` J)` A) i^i ((cls` J)` (X \ A))) C_ A)
64, 5syl6 25 . 2 |- ((J e. Top /\ A C_ X) -> (A e. (Clsd` J) -> (((cls` J)` A) i^i ((cls`
J)` (X \ A))) C_ A))
7 sslin 2819 . . . . . 6 |- ((((cls` J)` A) i^i ((cls`
J)` (X \ A))) C_ A -> ((X \ A) i^i (((cls`
J)` A) i^i ((cls` J)` (X \ A)))) C_ ((X \ A) i^i A))
87adantl 424 . . . . 5 |- (((J e. Top /\ A C_ X) /\ (((cls`
J)` A) i^i ((cls` J)` (X \ A))) C_ A) -> ((X \ A) i^i (((cls` J)` A) i^i ((cls` J)` (X \ A)))) C_ ((X \ A) i^i A))
9 incom 2787 . . . . . . 7 |- ((X \ A) i^i A) = (A i^i (X \ A))
10 difdisj 2945 . . . . . . 7 |- (A i^i (X \ A)) = (/)
119, 10eqtri 1908 . . . . . 6 |- ((X \ A) i^i A) = (/)
1211a1i 8 . . . . 5 |- (((J e. Top /\ A C_ X) /\ (((cls`
J)` A) i^i ((cls` J)` (X \ A))) C_ A) -> ((X \ A) i^i A) = (/))
13 sseq0 2903 . . . . 5 |- ((((X \ A) i^i (((cls` J)` A) i^i ((cls`
J)` (X \ A)))) C_ ((X \ A) i^i A) /\ ((X \ A) i^i A) = (/)) -> ((X \ A) i^i (((cls` J)` A) i^i ((cls` J)` (X \ A)))) = (/))
148, 12, 13syl11anc 524 . . . 4 |- (((J e. Top /\ A C_ X) /\ (((cls`
J)` A) i^i ((cls` J)` (X \ A))) C_ A) -> ((X \ A) i^i (((cls` J)` A) i^i ((cls` J)` (X \ A)))) = (/))
1514ex 402 . . 3 |- ((J e. Top /\ A C_ X) -> ((((cls`
J)` A) i^i ((cls` J)` (X \ A))) C_ A -> ((X \ A) i^i (((cls` J)` A) i^i ((cls` J)` (X \ A)))) = (/)))
16 dfss4 2827 . . . . . . . . . . 11 |- (A C_ X <-> (X \ (X \ A)) = A)
17 fveq2 4681 . . . . . . . . . . . 12 |- ((X \ (X \ A)) = A -> ((cls` J)` (X \ (X \ A))) = ((cls` J)` A))
1817eqcomd 1889 . . . . . . . . . . 11 |- ((X \ (X \ A)) = A -> ((cls` J)` A) = ((cls` J)` (X \ (X \ A))))
1916, 18sylbi 216 . . . . . . . . . 10 |- (A C_ X -> ((cls` J)` A) = ((cls` J)` (X \ (X \ A))))
2019adantl 424 . . . . . . . . 9 |- ((J e. Top /\ A C_ X) -> ((cls` J)` A) = ((cls` J)` (X \ (X \ A))))
2120ineq2d 2796 . . . . . . . 8 |- ((J e. Top /\ A C_ X) -> (((cls` J)` (X \ A)) i^i ((cls`
J)` A)) = (((cls` J)` (X \ A)) i^i ((cls`
J)` (X \ (X \ A)))))
22 incom 2787 . . . . . . . 8 |- (((cls` J)` A) i^i ((cls` J)` (X \ A))) = (((cls`
J)` (X \ A)) i^i ((cls` J)` A))
2321, 22syl5eq 1940 . . . . . . 7 |- ((J e. Top /\ A C_ X) -> (((cls` J)` A) i^i ((cls`
J)` (X \ A))) = (((cls` J)` (X \ A)) i^i ((cls`
J)` (X \ (X \ A)))))
2423ineq2d 2796 . . . . . 6 |- ((J e. Top /\ A C_ X) -> ((X \ A) i^i (((cls` J)` A) i^i ((cls` J)` (X \ A)))) = ((X \ A) i^i (((cls`
J)` (X \ A)) i^i ((cls` J)` (X \ (X \ A))))))
2524eqeq1d 1892 . . . . 5 |- ((J e. Top /\ A C_ X) -> (((X \ A) i^i (((cls` J)` A) i^i ((cls`
J)` (X \ A)))) = (/) <-> ((X \ A) i^i (((cls`
J)` (X \ A)) i^i ((cls` J)` (X \ (X \ A))))) = (/)))
26 difss 2735 . . . . . . 7 |- (X \ A) C_ X
271opnbnd 15409 . . . . . . 7 |- ((J e. Top /\ (X \ A) C_ X) -> ((X \ A) e. J <-> ((X \ A) i^i (((cls` J)` (X \ A)) i^i ((cls` J)` (X \ (X \ A))))) = (/)))
2826, 27mpan2 760 . . . . . 6 |- (J e. Top -> ((X \ A) e. J <-> ((X \ A) i^i (((cls`
J)` (X \ A)) i^i ((cls` J)` (X \ (X \ A))))) = (/)))
2928adantr 425 . . . . 5 |- ((J e. Top /\ A C_ X) -> ((X \ A) e. J <-> ((X \ A) i^i (((cls` J)` (X \ A)) i^i ((cls` J)` (X \ (X \ A))))) = (/)))
3025, 29bitr4d 590 . . . 4 |- ((J e. Top /\ A C_ X) -> (((X \ A) i^i (((cls` J)` A) i^i ((cls`
J)` (X \ A)))) = (/) <-> (X \ A) e. J))
311opncld 8950 . . . . . . 7 |- ((J e. Top /\ (X \ A) e. J) -> (X \ (X \ A)) e. (Clsd` J))
3231ex 402 . . . . . 6 |- (J e. Top -> ((X \ A) e. J -> (X \ (X \ A)) e. (Clsd` J)))
3332adantr 425 . . . . 5 |- ((J e. Top /\ A C_ X) -> ((X \ A) e. J -> (X \ (X \ A)) e. (Clsd` J)))
34 eleq1 1957 . . . . . . 7 |- ((X \ (X \ A)) = A -> ((X \ (X \ A)) e. (Clsd` J) <-> A e. (Clsd` J)))
3516, 34sylbi 216 . . . . . 6 |- (A C_ X -> ((X \ (X \ A)) e. (Clsd` J) <-> A e. (Clsd` J)))
3635adantl 424 . . . . 5 |- ((J e. Top /\ A C_ X) -> ((X \ (X \ A)) e. (Clsd` J) <-> A e. (Clsd` J)))
3733, 36sylibd 219 . . . 4 |- ((J e. Top /\ A C_ X) -> ((X \ A) e. J -> A e. (Clsd` J)))
3830, 37sylbid 220 . . 3 |- ((J e. Top /\ A C_ X) -> (((X \ A) i^i (((cls` J)` A) i^i ((cls`
J)` (X \ A)))) = (/) -> A e. (Clsd` J)))
3915, 38syld 30 . 2 |- ((J e. Top /\ A C_ X) -> ((((cls`
J)` A) i^i ((cls` J)` (X \ A))) C_ A -> A e. (Clsd` J)))
406, 39impbid 574 1 |- ((J e. Top /\ A C_ X) -> (A e. (Clsd` J) <-> (((cls` J)` A) i^i ((cls` J)` (X \ A))) C_ A))
Colors of variables: wff set class
Syntax hints:   -> wi 3   <-> wb 163   /\ wa 240   = wceq 1298   e. wcel 1300   \ cdif 2590   i^i cin 2592   C_ wss 2593  (/)c0 2875  U.cuni 3177  ` cfv 3998  Topctop 8857  Clsdccld 8936  clsccl 8938
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 1304  ax-gen 1305  ax-8 1306  ax-9 1307  ax-10 1308  ax-11 1309  ax-12 1310  ax-13 1311  ax-14 1312  ax-17 1317  ax-4 1319  ax-5o 1321  ax-6o 1324  ax-9o 1481  ax-10o 1500  ax-16 1580  ax-11o 1588  ax-ext 1865  ax-rep 3428  ax-sep 3438  ax-nul 3445  ax-pow 3481  ax-pr 3524  ax-un 3790
This theorem depends on definitions:  df-bi 164  df-or 241  df-an 242  df-3an 860  df-ex 1327  df-sb 1536  df-eu 1775  df-mo 1776  df-clab 1872  df-cleq 1877  df-clel 1880  df-ne 2019  df-ral 2109  df-rex 2110  df-rab 2112  df-v 2294  df-sbc 2454  df-csb 2541  df-dif 2597  df-un 2600  df-in 2603  df-ss 2605  df-nul 2876  df-pw 3035  df-sn 3049  df-pr 3050  df-op 3053  df-uni 3178  df-int 3215  df-iun 3257  df-iin 3258  df-br 3339  df-opab 3396  df-id 3586  df-xp 4000  df-rel 4001  df-cnv 4002  df-co 4003  df-dm 4004  df-rn 4005  df-res 4006  df-ima 4007  df-fun 4008  df-fn 4009  df-fv 4014  df-top 8861  df-cld 8939  df-ntr 8940  df-cls 8941
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