Metamath Proof Explorer


Theorem ntrneifv2

Description: If (pseudo-)interior and (pseudo-)neighborhood functions are related by the operator, F , then the function value of converse of F is the interior function. (Contributed by RP, 29-May-2021)

Ref Expression
Hypotheses ntrnei.o 𝑂 = ( 𝑖 ∈ V , 𝑗 ∈ V ↦ ( 𝑘 ∈ ( 𝒫 𝑗m 𝑖 ) ↦ ( 𝑙𝑗 ↦ { 𝑚𝑖𝑙 ∈ ( 𝑘𝑚 ) } ) ) )
ntrnei.f 𝐹 = ( 𝒫 𝐵 𝑂 𝐵 )
ntrnei.r ( 𝜑𝐼 𝐹 𝑁 )
Assertion ntrneifv2 ( 𝜑 → ( 𝐹𝑁 ) = 𝐼 )

Proof

Step Hyp Ref Expression
1 ntrnei.o 𝑂 = ( 𝑖 ∈ V , 𝑗 ∈ V ↦ ( 𝑘 ∈ ( 𝒫 𝑗m 𝑖 ) ↦ ( 𝑙𝑗 ↦ { 𝑚𝑖𝑙 ∈ ( 𝑘𝑚 ) } ) ) )
2 ntrnei.f 𝐹 = ( 𝒫 𝐵 𝑂 𝐵 )
3 ntrnei.r ( 𝜑𝐼 𝐹 𝑁 )
4 1 2 3 ntrneif1o ( 𝜑𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) )
5 1 2 3 ntrneinex ( 𝜑𝑁 ∈ ( 𝒫 𝒫 𝐵m 𝐵 ) )
6 dff1o3 ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) ↔ ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) ∧ Fun 𝐹 ) )
7 6 simprbi ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) → Fun 𝐹 )
8 7 adantr ( ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) ∧ 𝑁 ∈ ( 𝒫 𝒫 𝐵m 𝐵 ) ) → Fun 𝐹 )
9 df-rn ran 𝐹 = dom 𝐹
10 f1ofo ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) → 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) )
11 forn ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) → ran 𝐹 = ( 𝒫 𝒫 𝐵m 𝐵 ) )
12 10 11 syl ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) → ran 𝐹 = ( 𝒫 𝒫 𝐵m 𝐵 ) )
13 9 12 eqtr3id ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) → dom 𝐹 = ( 𝒫 𝒫 𝐵m 𝐵 ) )
14 13 eleq2d ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) → ( 𝑁 ∈ dom 𝐹𝑁 ∈ ( 𝒫 𝒫 𝐵m 𝐵 ) ) )
15 14 biimpar ( ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) ∧ 𝑁 ∈ ( 𝒫 𝒫 𝐵m 𝐵 ) ) → 𝑁 ∈ dom 𝐹 )
16 8 15 jca ( ( 𝐹 : ( 𝒫 𝐵m 𝒫 𝐵 ) –1-1-onto→ ( 𝒫 𝒫 𝐵m 𝐵 ) ∧ 𝑁 ∈ ( 𝒫 𝒫 𝐵m 𝐵 ) ) → ( Fun 𝐹𝑁 ∈ dom 𝐹 ) )
17 4 5 16 syl2anc ( 𝜑 → ( Fun 𝐹𝑁 ∈ dom 𝐹 ) )
18 funbrfvb ( ( Fun 𝐹𝑁 ∈ dom 𝐹 ) → ( ( 𝐹𝑁 ) = 𝐼𝑁 𝐹 𝐼 ) )
19 17 18 syl ( 𝜑 → ( ( 𝐹𝑁 ) = 𝐼𝑁 𝐹 𝐼 ) )
20 1 2 3 ntrneiiex ( 𝜑𝐼 ∈ ( 𝒫 𝐵m 𝒫 𝐵 ) )
21 brcnvg ( ( 𝑁 ∈ ( 𝒫 𝒫 𝐵m 𝐵 ) ∧ 𝐼 ∈ ( 𝒫 𝐵m 𝒫 𝐵 ) ) → ( 𝑁 𝐹 𝐼𝐼 𝐹 𝑁 ) )
22 5 20 21 syl2anc ( 𝜑 → ( 𝑁 𝐹 𝐼𝐼 𝐹 𝑁 ) )
23 19 22 bitrd ( 𝜑 → ( ( 𝐹𝑁 ) = 𝐼𝐼 𝐹 𝑁 ) )
24 3 23 mpbird ( 𝜑 → ( 𝐹𝑁 ) = 𝐼 )