Metamath Proof Explorer


Theorem tngds

Description: The metric function of a structure augmented with a norm. (Contributed by Mario Carneiro, 3-Oct-2015)

Ref Expression
Hypotheses tngbas.t 𝑇 = ( 𝐺 toNrmGrp 𝑁 )
tngds.2 = ( -g𝐺 )
Assertion tngds ( 𝑁𝑉 → ( 𝑁 ) = ( dist ‘ 𝑇 ) )

Proof

Step Hyp Ref Expression
1 tngbas.t 𝑇 = ( 𝐺 toNrmGrp 𝑁 )
2 tngds.2 = ( -g𝐺 )
3 dsid dist = Slot ( dist ‘ ndx )
4 9re 9 ∈ ℝ
5 1nn 1 ∈ ℕ
6 2nn0 2 ∈ ℕ0
7 9nn0 9 ∈ ℕ0
8 9lt10 9 < 1 0
9 5 6 7 8 declti 9 < 1 2
10 4 9 gtneii 1 2 ≠ 9
11 dsndx ( dist ‘ ndx ) = 1 2
12 tsetndx ( TopSet ‘ ndx ) = 9
13 11 12 neeq12i ( ( dist ‘ ndx ) ≠ ( TopSet ‘ ndx ) ↔ 1 2 ≠ 9 )
14 10 13 mpbir ( dist ‘ ndx ) ≠ ( TopSet ‘ ndx )
15 3 14 setsnid ( dist ‘ ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) ) = ( dist ‘ ( ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) sSet ⟨ ( TopSet ‘ ndx ) , ( MetOpen ‘ ( 𝑁 ) ) ⟩ ) )
16 2 fvexi ∈ V
17 coexg ( ( 𝑁𝑉 ∈ V ) → ( 𝑁 ) ∈ V )
18 16 17 mpan2 ( 𝑁𝑉 → ( 𝑁 ) ∈ V )
19 3 setsid ( ( 𝐺 ∈ V ∧ ( 𝑁 ) ∈ V ) → ( 𝑁 ) = ( dist ‘ ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) ) )
20 18 19 sylan2 ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( 𝑁 ) = ( dist ‘ ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) ) )
21 eqid ( 𝑁 ) = ( 𝑁 )
22 eqid ( MetOpen ‘ ( 𝑁 ) ) = ( MetOpen ‘ ( 𝑁 ) )
23 1 2 21 22 tngval ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → 𝑇 = ( ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) sSet ⟨ ( TopSet ‘ ndx ) , ( MetOpen ‘ ( 𝑁 ) ) ⟩ ) )
24 23 fveq2d ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( dist ‘ 𝑇 ) = ( dist ‘ ( ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) sSet ⟨ ( TopSet ‘ ndx ) , ( MetOpen ‘ ( 𝑁 ) ) ⟩ ) ) )
25 15 20 24 3eqtr4a ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( 𝑁 ) = ( dist ‘ 𝑇 ) )
26 co02 ( 𝑁 ∘ ∅ ) = ∅
27 df-ds dist = Slot 1 2
28 27 str0 ∅ = ( dist ‘ ∅ )
29 26 28 eqtri ( 𝑁 ∘ ∅ ) = ( dist ‘ ∅ )
30 fvprc ( ¬ 𝐺 ∈ V → ( -g𝐺 ) = ∅ )
31 2 30 syl5eq ( ¬ 𝐺 ∈ V → = ∅ )
32 31 coeq2d ( ¬ 𝐺 ∈ V → ( 𝑁 ) = ( 𝑁 ∘ ∅ ) )
33 reldmtng Rel dom toNrmGrp
34 33 ovprc1 ( ¬ 𝐺 ∈ V → ( 𝐺 toNrmGrp 𝑁 ) = ∅ )
35 1 34 syl5eq ( ¬ 𝐺 ∈ V → 𝑇 = ∅ )
36 35 fveq2d ( ¬ 𝐺 ∈ V → ( dist ‘ 𝑇 ) = ( dist ‘ ∅ ) )
37 29 32 36 3eqtr4a ( ¬ 𝐺 ∈ V → ( 𝑁 ) = ( dist ‘ 𝑇 ) )
38 37 adantr ( ( ¬ 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( 𝑁 ) = ( dist ‘ 𝑇 ) )
39 25 38 pm2.61ian ( 𝑁𝑉 → ( 𝑁 ) = ( dist ‘ 𝑇 ) )