Metamath Proof Explorer


Theorem ncvspds

Description: Value of the distance function in terms of the norm of a normed subcomplex vector space. Equation 1 of Kreyszig p. 59. (Contributed by NM, 28-Nov-2006) (Revised by AV, 13-Oct-2021)

Ref Expression
Hypotheses ncvspds.n ⊢ N = norm ⁡ G
ncvspds.x ⊢ X = Base G
ncvspds.p ⊢ + ˙ = + G
ncvspds.d ⊢ D = dist ⁡ G
ncvspds.s ⊢ · ˙ = ⋅ G
Assertion ncvspds ⊢ G ∈ NrmVec ∩ ℂVec ∧ A ∈ X ∧ B ∈ X → A D B = N ⁡ A + ˙ -1 · ˙ B

Proof

Step Hyp Ref Expression
1 ncvspds.n ⊢ N = norm ⁡ G
2 ncvspds.x ⊢ X = Base G
3 ncvspds.p ⊢ + ˙ = + G
4 ncvspds.d ⊢ D = dist ⁡ G
5 ncvspds.s ⊢ · ˙ = ⋅ G
6 elin ⊢ G ∈ NrmVec ∩ ℂVec ↔ G ∈ NrmVec ∧ G ∈ ℂVec
7 nvcnlm ⊢ G ∈ NrmVec → G ∈ NrmMod
8 nlmngp ⊢ G ∈ NrmMod → G ∈ NrmGrp
9 7 8 syl ⊢ G ∈ NrmVec → G ∈ NrmGrp
10 9 adantr ⊢ G ∈ NrmVec ∧ G ∈ ℂVec → G ∈ NrmGrp
11 6 10 sylbi ⊢ G ∈ NrmVec ∩ ℂVec → G ∈ NrmGrp
12 eqid ⊢ - G = - G
13 1 2 12 4 ngpds ⊢ G ∈ NrmGrp ∧ A ∈ X ∧ B ∈ X → A D B = N ⁡ A - G B
14 11 13 syl3an1 ⊢ G ∈ NrmVec ∩ ℂVec ∧ A ∈ X ∧ B ∈ X → A D B = N ⁡ A - G B
15 id ⊢ G ∈ ℂVec → G ∈ ℂVec
16 15 cvsclm ⊢ G ∈ ℂVec → G ∈ CMod
17 6 16 simplbiim ⊢ G ∈ NrmVec ∩ ℂVec → G ∈ CMod
18 eqid ⊢ Scalar ⁡ G = Scalar ⁡ G
19 2 3 12 18 5 clmvsubval ⊢ G ∈ CMod ∧ A ∈ X ∧ B ∈ X → A - G B = A + ˙ -1 · ˙ B
20 17 19 syl3an1 ⊢ G ∈ NrmVec ∩ ℂVec ∧ A ∈ X ∧ B ∈ X → A - G B = A + ˙ -1 · ˙ B
21 20 fveq2d ⊢ G ∈ NrmVec ∩ ℂVec ∧ A ∈ X ∧ B ∈ X → N ⁡ A - G B = N ⁡ A + ˙ -1 · ˙ B
22 14 21 eqtrd ⊢ G ∈ NrmVec ∩ ℂVec ∧ A ∈ X ∧ B ∈ X → A D B = N ⁡ A + ˙ -1 · ˙ B