Metamath Proof Explorer


Theorem pf1mulcl

Description: The product of multivariate polynomial functions. (Contributed by Mario Carneiro, 12-Jun-2015)

Ref Expression
Hypotheses pf1rcl.q ⊢ Q = ran ⁡ eval 1 ⁡ R
pf1mulcl.t ⊢ · ˙ = ⋅ R
Assertion pf1mulcl ⊢ F ∈ Q ∧ G ∈ Q → F · ˙ f G ∈ Q

Proof

Step Hyp Ref Expression
1 pf1rcl.q ⊢ Q = ran ⁡ eval 1 ⁡ R
2 pf1mulcl.t ⊢ · ˙ = ⋅ R
3 eqid ⊢ R ↑ 𝑠 Base R = R ↑ 𝑠 Base R
4 eqid ⊢ Base R ↑ 𝑠 Base R = Base R ↑ 𝑠 Base R
5 1 pf1rcl ⊢ F ∈ Q → R ∈ CRing
6 5 adantr ⊢ F ∈ Q ∧ G ∈ Q → R ∈ CRing
7 fvexd ⊢ F ∈ Q ∧ G ∈ Q → Base R ∈ V
8 eqid ⊢ Base R = Base R
9 1 8 pf1f ⊢ F ∈ Q → F : Base R ⟶ Base R
10 9 adantr ⊢ F ∈ Q ∧ G ∈ Q → F : Base R ⟶ Base R
11 fvex ⊢ Base R ∈ V
12 3 8 4 pwselbasb ⊢ R ∈ CRing ∧ Base R ∈ V → F ∈ Base R ↑ 𝑠 Base R ↔ F : Base R ⟶ Base R
13 6 11 12 sylancl ⊢ F ∈ Q ∧ G ∈ Q → F ∈ Base R ↑ 𝑠 Base R ↔ F : Base R ⟶ Base R
14 10 13 mpbird ⊢ F ∈ Q ∧ G ∈ Q → F ∈ Base R ↑ 𝑠 Base R
15 1 8 pf1f ⊢ G ∈ Q → G : Base R ⟶ Base R
16 15 adantl ⊢ F ∈ Q ∧ G ∈ Q → G : Base R ⟶ Base R
17 3 8 4 pwselbasb ⊢ R ∈ CRing ∧ Base R ∈ V → G ∈ Base R ↑ 𝑠 Base R ↔ G : Base R ⟶ Base R
18 6 11 17 sylancl ⊢ F ∈ Q ∧ G ∈ Q → G ∈ Base R ↑ 𝑠 Base R ↔ G : Base R ⟶ Base R
19 16 18 mpbird ⊢ F ∈ Q ∧ G ∈ Q → G ∈ Base R ↑ 𝑠 Base R
20 eqid ⊢ ⋅ R ↑ 𝑠 Base R = ⋅ R ↑ 𝑠 Base R
21 3 4 6 7 14 19 2 20 pwsmulrval ⊢ F ∈ Q ∧ G ∈ Q → F ⋅ R ↑ 𝑠 Base R G = F · ˙ f G
22 8 1 pf1subrg ⊢ R ∈ CRing → Q ∈ SubRing ⁡ R ↑ 𝑠 Base R
23 6 22 syl ⊢ F ∈ Q ∧ G ∈ Q → Q ∈ SubRing ⁡ R ↑ 𝑠 Base R
24 20 subrgmcl ⊢ Q ∈ SubRing ⁡ R ↑ 𝑠 Base R ∧ F ∈ Q ∧ G ∈ Q → F ⋅ R ↑ 𝑠 Base R G ∈ Q
25 24 3expib ⊢ Q ∈ SubRing ⁡ R ↑ 𝑠 Base R → F ∈ Q ∧ G ∈ Q → F ⋅ R ↑ 𝑠 Base R G ∈ Q
26 23 25 mpcom ⊢ F ∈ Q ∧ G ∈ Q → F ⋅ R ↑ 𝑠 Base R G ∈ Q
27 21 26 eqeltrrd ⊢ F ∈ Q ∧ G ∈ Q → F · ˙ f G ∈ Q