Metamath Proof Explorer


Theorem tngds

Description: The metric function of a structure augmented with a norm. (Contributed by Mario Carneiro, 3-Oct-2015) (Proof shortened by AV, 29-Oct-2024)

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 dsndxntsetndx ( dist ‘ ndx ) ≠ ( TopSet ‘ ndx )
5 3 4 setsnid ( dist ‘ ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) ) = ( dist ‘ ( ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) sSet ⟨ ( TopSet ‘ ndx ) , ( MetOpen ‘ ( 𝑁 ) ) ⟩ ) )
6 2 fvexi ∈ V
7 coexg ( ( 𝑁𝑉 ∈ V ) → ( 𝑁 ) ∈ V )
8 6 7 mpan2 ( 𝑁𝑉 → ( 𝑁 ) ∈ V )
9 3 setsid ( ( 𝐺 ∈ V ∧ ( 𝑁 ) ∈ V ) → ( 𝑁 ) = ( dist ‘ ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) ) )
10 8 9 sylan2 ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( 𝑁 ) = ( dist ‘ ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) ) )
11 eqid ( 𝑁 ) = ( 𝑁 )
12 eqid ( MetOpen ‘ ( 𝑁 ) ) = ( MetOpen ‘ ( 𝑁 ) )
13 1 2 11 12 tngval ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → 𝑇 = ( ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) sSet ⟨ ( TopSet ‘ ndx ) , ( MetOpen ‘ ( 𝑁 ) ) ⟩ ) )
14 13 fveq2d ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( dist ‘ 𝑇 ) = ( dist ‘ ( ( 𝐺 sSet ⟨ ( dist ‘ ndx ) , ( 𝑁 ) ⟩ ) sSet ⟨ ( TopSet ‘ ndx ) , ( MetOpen ‘ ( 𝑁 ) ) ⟩ ) ) )
15 5 10 14 3eqtr4a ( ( 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( 𝑁 ) = ( dist ‘ 𝑇 ) )
16 co02 ( 𝑁 ∘ ∅ ) = ∅
17 3 str0 ∅ = ( dist ‘ ∅ )
18 16 17 eqtri ( 𝑁 ∘ ∅ ) = ( dist ‘ ∅ )
19 fvprc ( ¬ 𝐺 ∈ V → ( -g𝐺 ) = ∅ )
20 2 19 syl5eq ( ¬ 𝐺 ∈ V → = ∅ )
21 20 coeq2d ( ¬ 𝐺 ∈ V → ( 𝑁 ) = ( 𝑁 ∘ ∅ ) )
22 reldmtng Rel dom toNrmGrp
23 22 ovprc1 ( ¬ 𝐺 ∈ V → ( 𝐺 toNrmGrp 𝑁 ) = ∅ )
24 1 23 syl5eq ( ¬ 𝐺 ∈ V → 𝑇 = ∅ )
25 24 fveq2d ( ¬ 𝐺 ∈ V → ( dist ‘ 𝑇 ) = ( dist ‘ ∅ ) )
26 18 21 25 3eqtr4a ( ¬ 𝐺 ∈ V → ( 𝑁 ) = ( dist ‘ 𝑇 ) )
27 26 adantr ( ( ¬ 𝐺 ∈ V ∧ 𝑁𝑉 ) → ( 𝑁 ) = ( dist ‘ 𝑇 ) )
28 15 27 pm2.61ian ( 𝑁𝑉 → ( 𝑁 ) = ( dist ‘ 𝑇 ) )