Metamath Proof Explorer


Theorem nglmle

Description: If the norm of each member of a converging sequence is less than or equal to a given amount, so is the norm of the convergence value. (Contributed by NM, 25-Dec-2007) (Revised by AV, 16-Oct-2021)

Ref Expression
Hypotheses nglmle.1 ⊢ X = Base G
nglmle.2 ⊢ D = dist ⁡ G ↾ X × X
nglmle.3 ⊢ J = MetOpen ⁡ D
nglmle.5 ⊢ N = norm ⁡ G
nglmle.6 ⊢ φ → G ∈ NrmGrp
nglmle.7 ⊢ φ → F : ℕ ⟶ X
nglmle.8 ⊢ φ → F ⇝t ⁡ J P
nglmle.9 ⊢ φ → R ∈ ℝ *
nglmle.10 ⊢ φ ∧ k ∈ ℕ → N ⁡ F ⁡ k ≤ R
Assertion nglmle ⊢ φ → N ⁡ P ≤ R

Proof

Step Hyp Ref Expression
1 nglmle.1 ⊢ X = Base G
2 nglmle.2 ⊢ D = dist ⁡ G ↾ X × X
3 nglmle.3 ⊢ J = MetOpen ⁡ D
4 nglmle.5 ⊢ N = norm ⁡ G
5 nglmle.6 ⊢ φ → G ∈ NrmGrp
6 nglmle.7 ⊢ φ → F : ℕ ⟶ X
7 nglmle.8 ⊢ φ → F ⇝t ⁡ J P
8 nglmle.9 ⊢ φ → R ∈ ℝ *
9 nglmle.10 ⊢ φ ∧ k ∈ ℕ → N ⁡ F ⁡ k ≤ R
10 ngpgrp ⊢ G ∈ NrmGrp → G ∈ Grp
11 5 10 syl ⊢ φ → G ∈ Grp
12 ngpms ⊢ G ∈ NrmGrp → G ∈ MetSp
13 5 12 syl ⊢ φ → G ∈ MetSp
14 msxms ⊢ G ∈ MetSp → G ∈ ∞MetSp
15 13 14 syl ⊢ φ → G ∈ ∞MetSp
16 1 2 xmsxmet ⊢ G ∈ ∞MetSp → D ∈ ∞Met ⁡ X
17 15 16 syl ⊢ φ → D ∈ ∞Met ⁡ X
18 3 mopntopon ⊢ D ∈ ∞Met ⁡ X → J ∈ TopOn ⁡ X
19 17 18 syl ⊢ φ → J ∈ TopOn ⁡ X
20 lmcl ⊢ J ∈ TopOn ⁡ X ∧ F ⇝t ⁡ J P → P ∈ X
21 19 7 20 syl2anc ⊢ φ → P ∈ X
22 eqid ⊢ 0 G = 0 G
23 eqid ⊢ dist ⁡ G = dist ⁡ G
24 4 1 22 23 2 nmval2 ⊢ G ∈ Grp ∧ P ∈ X → N ⁡ P = P D 0 G
25 11 21 24 syl2anc ⊢ φ → N ⁡ P = P D 0 G
26 1 22 grpidcl ⊢ G ∈ Grp → 0 G ∈ X
27 11 26 syl ⊢ φ → 0 G ∈ X
28 xmetsym ⊢ D ∈ ∞Met ⁡ X ∧ P ∈ X ∧ 0 G ∈ X → P D 0 G = 0 G D P
29 17 21 27 28 syl3anc ⊢ φ → P D 0 G = 0 G D P
30 25 29 eqtrd ⊢ φ → N ⁡ P = 0 G D P
31 nnuz ⊢ ℕ = ℤ ≥ 1
32 1zzd ⊢ φ → 1 ∈ ℤ
33 11 adantr ⊢ φ ∧ k ∈ ℕ → G ∈ Grp
34 6 ffvelcdmda ⊢ φ ∧ k ∈ ℕ → F ⁡ k ∈ X
35 4 1 22 23 2 nmval2 ⊢ G ∈ Grp ∧ F ⁡ k ∈ X → N ⁡ F ⁡ k = F ⁡ k D 0 G
36 33 34 35 syl2anc ⊢ φ ∧ k ∈ ℕ → N ⁡ F ⁡ k = F ⁡ k D 0 G
37 17 adantr ⊢ φ ∧ k ∈ ℕ → D ∈ ∞Met ⁡ X
38 27 adantr ⊢ φ ∧ k ∈ ℕ → 0 G ∈ X
39 xmetsym ⊢ D ∈ ∞Met ⁡ X ∧ F ⁡ k ∈ X ∧ 0 G ∈ X → F ⁡ k D 0 G = 0 G D F ⁡ k
40 37 34 38 39 syl3anc ⊢ φ ∧ k ∈ ℕ → F ⁡ k D 0 G = 0 G D F ⁡ k
41 36 40 eqtrd ⊢ φ ∧ k ∈ ℕ → N ⁡ F ⁡ k = 0 G D F ⁡ k
42 41 9 eqbrtrrd ⊢ φ ∧ k ∈ ℕ → 0 G D F ⁡ k ≤ R
43 31 3 17 32 7 27 8 42 lmle ⊢ φ → 0 G D P ≤ R
44 30 43 eqbrtrd ⊢ φ → N ⁡ P ≤ R