Metamath Proof Explorer


Theorem gsumsmonply1

Description: A finite group sum of scaled monomials is a univariate polynomial. (Contributed by AV, 8-Oct-2019)

Ref Expression
Hypotheses gsummonply1.p 𝑃 = ( Poly1𝑅 )
gsummonply1.b 𝐵 = ( Base ‘ 𝑃 )
gsummonply1.x 𝑋 = ( var1𝑅 )
gsummonply1.e = ( .g ‘ ( mulGrp ‘ 𝑃 ) )
gsummonply1.r ( 𝜑𝑅 ∈ Ring )
gsummonply1.k 𝐾 = ( Base ‘ 𝑅 )
gsummonply1.m = ( ·𝑠𝑃 )
gsummonply1.0 0 = ( 0g𝑅 )
gsummonply1.a ( 𝜑 → ∀ 𝑘 ∈ ℕ0 𝐴𝐾 )
gsummonply1.f ( 𝜑 → ( 𝑘 ∈ ℕ0𝐴 ) finSupp 0 )
Assertion gsumsmonply1 ( 𝜑 → ( 𝑃 Σg ( 𝑘 ∈ ℕ0 ↦ ( 𝐴 ( 𝑘 𝑋 ) ) ) ) ∈ 𝐵 )

Proof

Step Hyp Ref Expression
1 gsummonply1.p 𝑃 = ( Poly1𝑅 )
2 gsummonply1.b 𝐵 = ( Base ‘ 𝑃 )
3 gsummonply1.x 𝑋 = ( var1𝑅 )
4 gsummonply1.e = ( .g ‘ ( mulGrp ‘ 𝑃 ) )
5 gsummonply1.r ( 𝜑𝑅 ∈ Ring )
6 gsummonply1.k 𝐾 = ( Base ‘ 𝑅 )
7 gsummonply1.m = ( ·𝑠𝑃 )
8 gsummonply1.0 0 = ( 0g𝑅 )
9 gsummonply1.a ( 𝜑 → ∀ 𝑘 ∈ ℕ0 𝐴𝐾 )
10 gsummonply1.f ( 𝜑 → ( 𝑘 ∈ ℕ0𝐴 ) finSupp 0 )
11 eqid ( 0g𝑃 ) = ( 0g𝑃 )
12 1 ply1ring ( 𝑅 ∈ Ring → 𝑃 ∈ Ring )
13 ringcmn ( 𝑃 ∈ Ring → 𝑃 ∈ CMnd )
14 5 12 13 3syl ( 𝜑𝑃 ∈ CMnd )
15 nn0ex 0 ∈ V
16 15 a1i ( 𝜑 → ℕ0 ∈ V )
17 9 r19.21bi ( ( 𝜑𝑘 ∈ ℕ0 ) → 𝐴𝐾 )
18 5 3ad2ant1 ( ( 𝜑𝑘 ∈ ℕ0𝐴𝐾 ) → 𝑅 ∈ Ring )
19 simp3 ( ( 𝜑𝑘 ∈ ℕ0𝐴𝐾 ) → 𝐴𝐾 )
20 simp2 ( ( 𝜑𝑘 ∈ ℕ0𝐴𝐾 ) → 𝑘 ∈ ℕ0 )
21 eqid ( mulGrp ‘ 𝑃 ) = ( mulGrp ‘ 𝑃 )
22 6 1 3 7 21 4 2 ply1tmcl ( ( 𝑅 ∈ Ring ∧ 𝐴𝐾𝑘 ∈ ℕ0 ) → ( 𝐴 ( 𝑘 𝑋 ) ) ∈ 𝐵 )
23 18 19 20 22 syl3anc ( ( 𝜑𝑘 ∈ ℕ0𝐴𝐾 ) → ( 𝐴 ( 𝑘 𝑋 ) ) ∈ 𝐵 )
24 17 23 mpd3an3 ( ( 𝜑𝑘 ∈ ℕ0 ) → ( 𝐴 ( 𝑘 𝑋 ) ) ∈ 𝐵 )
25 24 fmpttd ( 𝜑 → ( 𝑘 ∈ ℕ0 ↦ ( 𝐴 ( 𝑘 𝑋 ) ) ) : ℕ0𝐵 )
26 1 ply1lmod ( 𝑅 ∈ Ring → 𝑃 ∈ LMod )
27 5 26 syl ( 𝜑𝑃 ∈ LMod )
28 1 ply1sca ( 𝑅 ∈ Ring → 𝑅 = ( Scalar ‘ 𝑃 ) )
29 5 28 syl ( 𝜑𝑅 = ( Scalar ‘ 𝑃 ) )
30 1 3 21 4 2 ply1moncl ( ( 𝑅 ∈ Ring ∧ 𝑘 ∈ ℕ0 ) → ( 𝑘 𝑋 ) ∈ 𝐵 )
31 5 30 sylan ( ( 𝜑𝑘 ∈ ℕ0 ) → ( 𝑘 𝑋 ) ∈ 𝐵 )
32 16 27 29 2 17 31 11 8 7 10 mptscmfsupp0 ( 𝜑 → ( 𝑘 ∈ ℕ0 ↦ ( 𝐴 ( 𝑘 𝑋 ) ) ) finSupp ( 0g𝑃 ) )
33 2 11 14 16 25 32 gsumcl ( 𝜑 → ( 𝑃 Σg ( 𝑘 ∈ ℕ0 ↦ ( 𝐴 ( 𝑘 𝑋 ) ) ) ) ∈ 𝐵 )