Metamath Proof Explorer


Theorem fourierdlem36

Description: F is an isomorphism. (Contributed by Glauco Siliprandi, 11-Dec-2019)

Ref Expression
Hypotheses fourierdlem36.a ⊢ φ → A ∈ Fin
fourierdlem36.assr ⊢ φ → A ⊆ ℝ
fourierdlem36.f ⊢ F = ι f | f Isom < , < 0 … N A
fourierdlem36.n ⊢ N = A − 1
Assertion fourierdlem36 ⊢ φ → F Isom < , < 0 … N A

Proof

Step Hyp Ref Expression
1 fourierdlem36.a ⊢ φ → A ∈ Fin
2 fourierdlem36.assr ⊢ φ → A ⊆ ℝ
3 fourierdlem36.f ⊢ F = ι f | f Isom < , < 0 … N A
4 fourierdlem36.n ⊢ N = A − 1
5 ltso ⊢ < Or ℝ
6 soss ⊢ A ⊆ ℝ → < Or ℝ → < Or A
7 2 5 6 mpisyl ⊢ φ → < Or A
8 0zd ⊢ φ → 0 ∈ ℤ
9 eqid ⊢ A + 0 - 1 = A + 0 - 1
10 1 7 8 9 fzisoeu ⊢ φ → ∃! f f Isom < , < 0 … A + 0 - 1 A
11 hashcl ⊢ A ∈ Fin → A ∈ ℕ 0
12 1 11 syl ⊢ φ → A ∈ ℕ 0
13 12 nn0cnd ⊢ φ → A ∈ ℂ
14 1cnd ⊢ φ → 1 ∈ ℂ
15 13 14 negsubd ⊢ φ → A + -1 = A − 1
16 df-neg ⊢ − 1 = 0 − 1
17 16 eqcomi ⊢ 0 − 1 = − 1
18 17 oveq2i ⊢ A + 0 - 1 = A + -1
19 15 18 4 3eqtr4g ⊢ φ → A + 0 - 1 = N
20 19 oveq2d ⊢ φ → 0 … A + 0 - 1 = 0 … N
21 isoeq4 ⊢ 0 … A + 0 - 1 = 0 … N → f Isom < , < 0 … A + 0 - 1 A ↔ f Isom < , < 0 … N A
22 20 21 syl ⊢ φ → f Isom < , < 0 … A + 0 - 1 A ↔ f Isom < , < 0 … N A
23 22 eubidv ⊢ φ → ∃! f f Isom < , < 0 … A + 0 - 1 A ↔ ∃! f f Isom < , < 0 … N A
24 10 23 mpbid ⊢ φ → ∃! f f Isom < , < 0 … N A
25 iotacl ⊢ ∃! f f Isom < , < 0 … N A → ι f | f Isom < , < 0 … N A ∈ f | f Isom < , < 0 … N A
26 24 25 syl ⊢ φ → ι f | f Isom < , < 0 … N A ∈ f | f Isom < , < 0 … N A
27 3 26 eqeltrid ⊢ φ → F ∈ f | f Isom < , < 0 … N A
28 iotaex ⊢ ι f | f Isom < , < 0 … N A ∈ V
29 3 28 eqeltri ⊢ F ∈ V
30 isoeq1 ⊢ f = F → f Isom < , < 0 … N A ↔ F Isom < , < 0 … N A
31 29 30 elab ⊢ F ∈ f | f Isom < , < 0 … N A ↔ F Isom < , < 0 … N A
32 27 31 sylib ⊢ φ → F Isom < , < 0 … N A