Metamath Proof Explorer


Theorem deg1pw

Description: Exact degree of a variable power over a nontrivial ring. (Contributed by Stefan O'Rear, 1-Apr-2015)

Ref Expression
Hypotheses deg1pw.d ⊢ D = deg 1 ⁡ R
deg1pw.p ⊢ P = Poly 1 ⁡ R
deg1pw.x ⊢ X = var 1 ⁡ R
deg1pw.n ⊢ N = mulGrp P
deg1pw.e ⊢ × ˙ = ⋅ N
Assertion deg1pw ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → D ⁡ F × ˙ X = F

Proof

Step Hyp Ref Expression
1 deg1pw.d ⊢ D = deg 1 ⁡ R
2 deg1pw.p ⊢ P = Poly 1 ⁡ R
3 deg1pw.x ⊢ X = var 1 ⁡ R
4 deg1pw.n ⊢ N = mulGrp P
5 deg1pw.e ⊢ × ˙ = ⋅ N
6 2 ply1sca ⊢ R ∈ NzRing → R = Scalar ⁡ P
7 6 adantr ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → R = Scalar ⁡ P
8 7 fveq2d ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → 1 R = 1 Scalar ⁡ P
9 8 oveq1d ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → 1 R ⋅ P F × ˙ X = 1 Scalar ⁡ P ⋅ P F × ˙ X
10 nzrring ⊢ R ∈ NzRing → R ∈ Ring
11 10 adantr ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → R ∈ Ring
12 2 ply1lmod ⊢ R ∈ Ring → P ∈ LMod
13 11 12 syl ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → P ∈ LMod
14 eqid ⊢ Base P = Base P
15 4 14 mgpbas ⊢ Base P = Base N
16 2 ply1ring ⊢ R ∈ Ring → P ∈ Ring
17 4 ringmgp ⊢ P ∈ Ring → N ∈ Mnd
18 11 16 17 3syl ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → N ∈ Mnd
19 simpr ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → F ∈ ℕ 0
20 3 2 14 vr1cl ⊢ R ∈ Ring → X ∈ Base P
21 11 20 syl ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → X ∈ Base P
22 15 5 18 19 21 mulgnn0cld ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → F × ˙ X ∈ Base P
23 eqid ⊢ Scalar ⁡ P = Scalar ⁡ P
24 eqid ⊢ ⋅ P = ⋅ P
25 eqid ⊢ 1 Scalar ⁡ P = 1 Scalar ⁡ P
26 14 23 24 25 lmodvs1 ⊢ P ∈ LMod ∧ F × ˙ X ∈ Base P → 1 Scalar ⁡ P ⋅ P F × ˙ X = F × ˙ X
27 13 22 26 syl2anc ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → 1 Scalar ⁡ P ⋅ P F × ˙ X = F × ˙ X
28 9 27 eqtrd ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → 1 R ⋅ P F × ˙ X = F × ˙ X
29 28 fveq2d ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → D ⁡ 1 R ⋅ P F × ˙ X = D ⁡ F × ˙ X
30 eqid ⊢ Base R = Base R
31 eqid ⊢ 1 R = 1 R
32 30 31 ringidcl ⊢ R ∈ Ring → 1 R ∈ Base R
33 11 32 syl ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → 1 R ∈ Base R
34 eqid ⊢ 0 R = 0 R
35 31 34 nzrnz ⊢ R ∈ NzRing → 1 R ≠ 0 R
36 35 adantr ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → 1 R ≠ 0 R
37 1 30 2 3 24 4 5 34 deg1tm ⊢ R ∈ Ring ∧ 1 R ∈ Base R ∧ 1 R ≠ 0 R ∧ F ∈ ℕ 0 → D ⁡ 1 R ⋅ P F × ˙ X = F
38 11 33 36 19 37 syl121anc ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → D ⁡ 1 R ⋅ P F × ˙ X = F
39 29 38 eqtr3d ⊢ R ∈ NzRing ∧ F ∈ ℕ 0 → D ⁡ F × ˙ X = F