Metamath Proof Explorer


Theorem ulmuni

Description: A sequence of functions uniformly converges to at most one limit. (Contributed by Mario Carneiro, 5-Jul-2017)

Ref Expression
Assertion ulmuni ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H → G = H

Proof

Step Hyp Ref Expression
1 ulmcl ⊢ F ⇝u ⁡ S G → G : S ⟶ ℂ
2 1 adantr ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H → G : S ⟶ ℂ
3 2 ffnd ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H → G Fn S
4 ulmcl ⊢ F ⇝u ⁡ S H → H : S ⟶ ℂ
5 4 adantl ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H → H : S ⟶ ℂ
6 5 ffnd ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H → H Fn S
7 eqid ⊢ ℤ ≥ n = ℤ ≥ n
8 simplr ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → n ∈ ℤ
9 simpr ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → F : ℤ ≥ n ⟶ ℂ S
10 simpllr ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → x ∈ S
11 fvex ⊢ ℤ ≥ n ∈ V
12 11 mptex ⊢ i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ∈ V
13 12 a1i ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ∈ V
14 fveq2 ⊢ i = k → F ⁡ i = F ⁡ k
15 14 fveq1d ⊢ i = k → F ⁡ i ⁡ x = F ⁡ k ⁡ x
16 eqid ⊢ i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x = i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x
17 fvex ⊢ F ⁡ k ⁡ x ∈ V
18 15 16 17 fvmpt ⊢ k ∈ ℤ ≥ n → i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⁡ k = F ⁡ k ⁡ x
19 18 eqcomd ⊢ k ∈ ℤ ≥ n → F ⁡ k ⁡ x = i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⁡ k
20 19 adantl ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S ∧ k ∈ ℤ ≥ n → F ⁡ k ⁡ x = i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⁡ k
21 simp-4l ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → F ⇝u ⁡ S G
22 7 8 9 10 13 20 21 ulmclm ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⇝ G ⁡ x
23 simp-4r ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → F ⇝u ⁡ S H
24 7 8 9 10 13 20 23 ulmclm ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⇝ H ⁡ x
25 climuni ⊢ i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⇝ G ⁡ x ∧ i ∈ ℤ ≥ n ⟼ F ⁡ i ⁡ x ⇝ H ⁡ x → G ⁡ x = H ⁡ x
26 22 24 25 syl2anc ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S ∧ n ∈ ℤ ∧ F : ℤ ≥ n ⟶ ℂ S → G ⁡ x = H ⁡ x
27 ulmf ⊢ F ⇝u ⁡ S G → ∃ n ∈ ℤ F : ℤ ≥ n ⟶ ℂ S
28 27 ad2antrr ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S → ∃ n ∈ ℤ F : ℤ ≥ n ⟶ ℂ S
29 26 28 r19.29a ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H ∧ x ∈ S → G ⁡ x = H ⁡ x
30 3 6 29 eqfnfvd ⊢ F ⇝u ⁡ S G ∧ F ⇝u ⁡ S H → G = H