Metamath Proof Explorer


Theorem dssmapntrcls

Description: The interior and closure operators on a topology are duals of each other. See also kur14lem2 . (Contributed by RP, 21-Apr-2021)

Ref Expression
Hypotheses dssmapclsntr.x 𝑋 = 𝐽
dssmapclsntr.k 𝐾 = ( cls ‘ 𝐽 )
dssmapclsntr.i 𝐼 = ( int ‘ 𝐽 )
dssmapclsntr.o 𝑂 = ( 𝑏 ∈ V ↦ ( 𝑓 ∈ ( 𝒫 𝑏m 𝒫 𝑏 ) ↦ ( 𝑠 ∈ 𝒫 𝑏 ↦ ( 𝑏 ∖ ( 𝑓 ‘ ( 𝑏𝑠 ) ) ) ) ) )
dssmapclsntr.d 𝐷 = ( 𝑂𝑋 )
Assertion dssmapntrcls ( 𝐽 ∈ Top → 𝐼 = ( 𝐷𝐾 ) )

Proof

Step Hyp Ref Expression
1 dssmapclsntr.x 𝑋 = 𝐽
2 dssmapclsntr.k 𝐾 = ( cls ‘ 𝐽 )
3 dssmapclsntr.i 𝐼 = ( int ‘ 𝐽 )
4 dssmapclsntr.o 𝑂 = ( 𝑏 ∈ V ↦ ( 𝑓 ∈ ( 𝒫 𝑏m 𝒫 𝑏 ) ↦ ( 𝑠 ∈ 𝒫 𝑏 ↦ ( 𝑏 ∖ ( 𝑓 ‘ ( 𝑏𝑠 ) ) ) ) ) )
5 dssmapclsntr.d 𝐷 = ( 𝑂𝑋 )
6 vpwex 𝒫 𝑡 ∈ V
7 6 inex2 ( 𝐽 ∩ 𝒫 𝑡 ) ∈ V
8 7 uniex ( 𝐽 ∩ 𝒫 𝑡 ) ∈ V
9 8 rgenw 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ∈ V
10 nfcv 𝑡 𝒫 𝑋
11 10 fnmptf ( ∀ 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ∈ V → ( 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ) Fn 𝒫 𝑋 )
12 9 11 mp1i ( 𝐽 ∈ Top → ( 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ) Fn 𝒫 𝑋 )
13 1 ntrfval ( 𝐽 ∈ Top → ( int ‘ 𝐽 ) = ( 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ) )
14 3 13 syl5eq ( 𝐽 ∈ Top → 𝐼 = ( 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ) )
15 14 fneq1d ( 𝐽 ∈ Top → ( 𝐼 Fn 𝒫 𝑋 ↔ ( 𝑡 ∈ 𝒫 𝑋 ( 𝐽 ∩ 𝒫 𝑡 ) ) Fn 𝒫 𝑋 ) )
16 12 15 mpbird ( 𝐽 ∈ Top → 𝐼 Fn 𝒫 𝑋 )
17 1 topopn ( 𝐽 ∈ Top → 𝑋𝐽 )
18 4 5 17 dssmapf1od ( 𝐽 ∈ Top → 𝐷 : ( 𝒫 𝑋m 𝒫 𝑋 ) –1-1-onto→ ( 𝒫 𝑋m 𝒫 𝑋 ) )
19 f1of ( 𝐷 : ( 𝒫 𝑋m 𝒫 𝑋 ) –1-1-onto→ ( 𝒫 𝑋m 𝒫 𝑋 ) → 𝐷 : ( 𝒫 𝑋m 𝒫 𝑋 ) ⟶ ( 𝒫 𝑋m 𝒫 𝑋 ) )
20 18 19 syl ( 𝐽 ∈ Top → 𝐷 : ( 𝒫 𝑋m 𝒫 𝑋 ) ⟶ ( 𝒫 𝑋m 𝒫 𝑋 ) )
21 1 2 clselmap ( 𝐽 ∈ Top → 𝐾 ∈ ( 𝒫 𝑋m 𝒫 𝑋 ) )
22 20 21 ffvelrnd ( 𝐽 ∈ Top → ( 𝐷𝐾 ) ∈ ( 𝒫 𝑋m 𝒫 𝑋 ) )
23 elmapfn ( ( 𝐷𝐾 ) ∈ ( 𝒫 𝑋m 𝒫 𝑋 ) → ( 𝐷𝐾 ) Fn 𝒫 𝑋 )
24 22 23 syl ( 𝐽 ∈ Top → ( 𝐷𝐾 ) Fn 𝒫 𝑋 )
25 elpwi ( 𝑡 ∈ 𝒫 𝑋𝑡𝑋 )
26 1 ntrval2 ( ( 𝐽 ∈ Top ∧ 𝑡𝑋 ) → ( ( int ‘ 𝐽 ) ‘ 𝑡 ) = ( 𝑋 ∖ ( ( cls ‘ 𝐽 ) ‘ ( 𝑋𝑡 ) ) ) )
27 25 26 sylan2 ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → ( ( int ‘ 𝐽 ) ‘ 𝑡 ) = ( 𝑋 ∖ ( ( cls ‘ 𝐽 ) ‘ ( 𝑋𝑡 ) ) ) )
28 3 fveq1i ( 𝐼𝑡 ) = ( ( int ‘ 𝐽 ) ‘ 𝑡 )
29 2 fveq1i ( 𝐾 ‘ ( 𝑋𝑡 ) ) = ( ( cls ‘ 𝐽 ) ‘ ( 𝑋𝑡 ) )
30 29 difeq2i ( 𝑋 ∖ ( 𝐾 ‘ ( 𝑋𝑡 ) ) ) = ( 𝑋 ∖ ( ( cls ‘ 𝐽 ) ‘ ( 𝑋𝑡 ) ) )
31 27 28 30 3eqtr4g ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → ( 𝐼𝑡 ) = ( 𝑋 ∖ ( 𝐾 ‘ ( 𝑋𝑡 ) ) ) )
32 17 adantr ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → 𝑋𝐽 )
33 21 adantr ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → 𝐾 ∈ ( 𝒫 𝑋m 𝒫 𝑋 ) )
34 eqid ( 𝐷𝐾 ) = ( 𝐷𝐾 )
35 simpr ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → 𝑡 ∈ 𝒫 𝑋 )
36 eqid ( ( 𝐷𝐾 ) ‘ 𝑡 ) = ( ( 𝐷𝐾 ) ‘ 𝑡 )
37 4 5 32 33 34 35 36 dssmapfv3d ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → ( ( 𝐷𝐾 ) ‘ 𝑡 ) = ( 𝑋 ∖ ( 𝐾 ‘ ( 𝑋𝑡 ) ) ) )
38 31 37 eqtr4d ( ( 𝐽 ∈ Top ∧ 𝑡 ∈ 𝒫 𝑋 ) → ( 𝐼𝑡 ) = ( ( 𝐷𝐾 ) ‘ 𝑡 ) )
39 16 24 38 eqfnfvd ( 𝐽 ∈ Top → 𝐼 = ( 𝐷𝐾 ) )