Theorem coemulhi 24447

Description: The leading coefficient of a product of polynomials. (Contributed by Mario Carneiro, 24-Jul-2014.)

Hypotheses

Ref	Expression
coefv0.1	⊢ 𝐴 = (coeff‘𝐹)
coeadd.2	⊢ 𝐵 = (coeff‘𝐺)
coemulhi.3	⊢ 𝑀 = (deg‘𝐹)
coemulhi.4	⊢ 𝑁 = (deg‘𝐺)

Assertion

Ref	Expression
coemulhi	⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((coeff‘(𝐹 ∘𝑓 · 𝐺))‘(𝑀 + 𝑁)) = ((𝐴‘𝑀) · (𝐵‘𝑁)))

Proof of Theorem coemulhi

Dummy variable 𝑘 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		coemulhi.3	. . . . 5 ⊢ 𝑀 = (deg‘𝐹)
2		dgrcl 24426	. . . . 5 ⊢ (𝐹 ∈ (Poly‘𝑆) → (deg‘𝐹) ∈ ℕ0)
3	1, 2	syl5eqel 2863	. . . 4 ⊢ (𝐹 ∈ (Poly‘𝑆) → 𝑀 ∈ ℕ0)
4		coemulhi.4	. . . . 5 ⊢ 𝑁 = (deg‘𝐺)
5		dgrcl 24426	. . . . 5 ⊢ (𝐺 ∈ (Poly‘𝑆) → (deg‘𝐺) ∈ ℕ0)
6	4, 5	syl5eqel 2863	. . . 4 ⊢ (𝐺 ∈ (Poly‘𝑆) → 𝑁 ∈ ℕ0)
7		nn0addcl 11679	. . . 4 ⊢ ((𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0) → (𝑀 + 𝑁) ∈ ℕ0)
8	3, 6, 7	syl2an 589	. . 3 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (𝑀 + 𝑁) ∈ ℕ0)
9		coefv0.1	. . . 4 ⊢ 𝐴 = (coeff‘𝐹)
10		coeadd.2	. . . 4 ⊢ 𝐵 = (coeff‘𝐺)
11	9, 10	coemul 24445	. . 3 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆) ∧ (𝑀 + 𝑁) ∈ ℕ0) → ((coeff‘(𝐹 ∘𝑓 · 𝐺))‘(𝑀 + 𝑁)) = Σ𝑘 ∈ (0...(𝑀 + 𝑁))((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))))
12	8, 11	mpd3an3 1535	. 2 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((coeff‘(𝐹 ∘𝑓 · 𝐺))‘(𝑀 + 𝑁)) = Σ𝑘 ∈ (0...(𝑀 + 𝑁))((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))))
13	6	adantl 475	. . . . . . 7 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑁 ∈ ℕ0)
14	13	nn0ge0d 11705	. . . . . 6 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 0 ≤ 𝑁)
15	3	adantr 474	. . . . . . . 8 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑀 ∈ ℕ0)
16	15	nn0red 11703	. . . . . . 7 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑀 ∈ ℝ)
17	13	nn0red 11703	. . . . . . 7 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑁 ∈ ℝ)
18	16, 17	addge01d 10963	. . . . . 6 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (0 ≤ 𝑁 ↔ 𝑀 ≤ (𝑀 + 𝑁)))
19	14, 18	mpbid 224	. . . . 5 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑀 ≤ (𝑀 + 𝑁))
20		nn0uz 12028	. . . . . . 7 ⊢ ℕ0 = (ℤ≥‘0)
21	15, 20	syl6eleq 2869	. . . . . 6 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑀 ∈ (ℤ≥‘0))
22	8	nn0zd 11832	. . . . . 6 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (𝑀 + 𝑁) ∈ ℤ)
23		elfz5 12651	. . . . . 6 ⊢ ((𝑀 ∈ (ℤ≥‘0) ∧ (𝑀 + 𝑁) ∈ ℤ) → (𝑀 ∈ (0...(𝑀 + 𝑁)) ↔ 𝑀 ≤ (𝑀 + 𝑁)))
24	21, 22, 23	syl2anc 579	. . . . 5 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (𝑀 ∈ (0...(𝑀 + 𝑁)) ↔ 𝑀 ≤ (𝑀 + 𝑁)))
25	19, 24	mpbird 249	. . . 4 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑀 ∈ (0...(𝑀 + 𝑁)))
26	25	snssd 4571	. . 3 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → {𝑀} ⊆ (0...(𝑀 + 𝑁)))
27		elsni 4415	. . . . . 6 ⊢ (𝑘 ∈ {𝑀} → 𝑘 = 𝑀)
28	27	adantl 475	. . . . 5 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ {𝑀}) → 𝑘 = 𝑀)
29		fveq2 6446	. . . . . 6 ⊢ (𝑘 = 𝑀 → (𝐴‘𝑘) = (𝐴‘𝑀))
30		oveq2 6930	. . . . . . 7 ⊢ (𝑘 = 𝑀 → ((𝑀 + 𝑁) − 𝑘) = ((𝑀 + 𝑁) − 𝑀))
31	30	fveq2d 6450	. . . . . 6 ⊢ (𝑘 = 𝑀 → (𝐵‘((𝑀 + 𝑁) − 𝑘)) = (𝐵‘((𝑀 + 𝑁) − 𝑀)))
32	29, 31	oveq12d 6940	. . . . 5 ⊢ (𝑘 = 𝑀 → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))))
33	28, 32	syl 17	. . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ {𝑀}) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))))
34	16	recnd 10405	. . . . . . . . 9 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑀 ∈ ℂ)
35	17	recnd 10405	. . . . . . . . 9 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝑁 ∈ ℂ)
36	34, 35	pncan2d 10736	. . . . . . . 8 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((𝑀 + 𝑁) − 𝑀) = 𝑁)
37	36	fveq2d 6450	. . . . . . 7 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (𝐵‘((𝑀 + 𝑁) − 𝑀)) = (𝐵‘𝑁))
38	37	oveq2d 6938	. . . . . 6 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))) = ((𝐴‘𝑀) · (𝐵‘𝑁)))
39	9	coef3 24425	. . . . . . . . 9 ⊢ (𝐹 ∈ (Poly‘𝑆) → 𝐴:ℕ0⟶ℂ)
40	39	adantr 474	. . . . . . . 8 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝐴:ℕ0⟶ℂ)
41	40, 15	ffvelrnd 6624	. . . . . . 7 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (𝐴‘𝑀) ∈ ℂ)
42	10	coef3 24425	. . . . . . . . 9 ⊢ (𝐺 ∈ (Poly‘𝑆) → 𝐵:ℕ0⟶ℂ)
43	42	adantl 475	. . . . . . . 8 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝐵:ℕ0⟶ℂ)
44	43, 13	ffvelrnd 6624	. . . . . . 7 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (𝐵‘𝑁) ∈ ℂ)
45	41, 44	mulcld 10397	. . . . . 6 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((𝐴‘𝑀) · (𝐵‘𝑁)) ∈ ℂ)
46	38, 45	eqeltrd 2859	. . . . 5 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))) ∈ ℂ)
47	46	adantr 474	. . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ {𝑀}) → ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))) ∈ ℂ)
48	33, 47	eqeltrd 2859	. . 3 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ {𝑀}) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) ∈ ℂ)
49		simpl 476	. . . . . . . . 9 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝐹 ∈ (Poly‘𝑆))
50		eldifi 3955	. . . . . . . . . 10 ⊢ (𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀}) → 𝑘 ∈ (0...(𝑀 + 𝑁)))
51		elfznn0 12751	. . . . . . . . . 10 ⊢ (𝑘 ∈ (0...(𝑀 + 𝑁)) → 𝑘 ∈ ℕ0)
52	50, 51	syl 17	. . . . . . . . 9 ⊢ (𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀}) → 𝑘 ∈ ℕ0)
53	9, 1	dgrub 24427	. . . . . . . . . 10 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑘 ∈ ℕ0 ∧ (𝐴‘𝑘) ≠ 0) → 𝑘 ≤ 𝑀)
54	53	3expia 1111	. . . . . . . . 9 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝑘 ∈ ℕ0) → ((𝐴‘𝑘) ≠ 0 → 𝑘 ≤ 𝑀))
55	49, 52, 54	syl2an 589	. . . . . . . 8 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → ((𝐴‘𝑘) ≠ 0 → 𝑘 ≤ 𝑀))
56	55	necon1bd 2987	. . . . . . 7 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (¬ 𝑘 ≤ 𝑀 → (𝐴‘𝑘) = 0))
57	56	imp 397	. . . . . 6 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → (𝐴‘𝑘) = 0)
58	57	oveq1d 6937	. . . . 5 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = (0 · (𝐵‘((𝑀 + 𝑁) − 𝑘))))
59	43	ad2antrr 716	. . . . . . 7 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → 𝐵:ℕ0⟶ℂ)
60	50	ad2antlr 717	. . . . . . . 8 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → 𝑘 ∈ (0...(𝑀 + 𝑁)))
61		fznn0sub 12690	. . . . . . . 8 ⊢ (𝑘 ∈ (0...(𝑀 + 𝑁)) → ((𝑀 + 𝑁) − 𝑘) ∈ ℕ0)
62	60, 61	syl 17	. . . . . . 7 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → ((𝑀 + 𝑁) − 𝑘) ∈ ℕ0)
63	59, 62	ffvelrnd 6624	. . . . . 6 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → (𝐵‘((𝑀 + 𝑁) − 𝑘)) ∈ ℂ)
64	63	mul02d 10574	. . . . 5 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → (0 · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = 0)
65	58, 64	eqtrd 2814	. . . 4 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑘 ≤ 𝑀) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = 0)
66	16	adantr 474	. . . . . . . . . . 11 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → 𝑀 ∈ ℝ)
67	50	adantl 475	. . . . . . . . . . . . 13 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → 𝑘 ∈ (0...(𝑀 + 𝑁)))
68	67, 51	syl 17	. . . . . . . . . . . 12 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → 𝑘 ∈ ℕ0)
69	68	nn0red 11703	. . . . . . . . . . 11 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → 𝑘 ∈ ℝ)
70	17	adantr 474	. . . . . . . . . . 11 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → 𝑁 ∈ ℝ)
71	66, 69, 70	leadd1d 10969	. . . . . . . . . 10 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (𝑀 ≤ 𝑘 ↔ (𝑀 + 𝑁) ≤ (𝑘 + 𝑁)))
72	8	adantr 474	. . . . . . . . . . . 12 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (𝑀 + 𝑁) ∈ ℕ0)
73	72	nn0red 11703	. . . . . . . . . . 11 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (𝑀 + 𝑁) ∈ ℝ)
74	73, 69, 70	lesubadd2d 10974	. . . . . . . . . 10 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (((𝑀 + 𝑁) − 𝑘) ≤ 𝑁 ↔ (𝑀 + 𝑁) ≤ (𝑘 + 𝑁)))
75	71, 74	bitr4d 274	. . . . . . . . 9 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (𝑀 ≤ 𝑘 ↔ ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁))
76	75	notbid 310	. . . . . . . 8 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (¬ 𝑀 ≤ 𝑘 ↔ ¬ ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁))
77	76	biimpa 470	. . . . . . 7 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → ¬ ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁)
78		simpr 479	. . . . . . . . . 10 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → 𝐺 ∈ (Poly‘𝑆))
79	50, 61	syl 17	. . . . . . . . . 10 ⊢ (𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀}) → ((𝑀 + 𝑁) − 𝑘) ∈ ℕ0)
80	10, 4	dgrub 24427	. . . . . . . . . . 11 ⊢ ((𝐺 ∈ (Poly‘𝑆) ∧ ((𝑀 + 𝑁) − 𝑘) ∈ ℕ0 ∧ (𝐵‘((𝑀 + 𝑁) − 𝑘)) ≠ 0) → ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁)
81	80	3expia 1111	. . . . . . . . . 10 ⊢ ((𝐺 ∈ (Poly‘𝑆) ∧ ((𝑀 + 𝑁) − 𝑘) ∈ ℕ0) → ((𝐵‘((𝑀 + 𝑁) − 𝑘)) ≠ 0 → ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁))
82	78, 79, 81	syl2an 589	. . . . . . . . 9 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → ((𝐵‘((𝑀 + 𝑁) − 𝑘)) ≠ 0 → ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁))
83	82	necon1bd 2987	. . . . . . . 8 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (¬ ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁 → (𝐵‘((𝑀 + 𝑁) − 𝑘)) = 0))
84	83	imp 397	. . . . . . 7 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ ((𝑀 + 𝑁) − 𝑘) ≤ 𝑁) → (𝐵‘((𝑀 + 𝑁) − 𝑘)) = 0)
85	77, 84	syldan 585	. . . . . 6 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → (𝐵‘((𝑀 + 𝑁) − 𝑘)) = 0)
86	85	oveq2d 6938	. . . . 5 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = ((𝐴‘𝑘) · 0))
87	40	ad2antrr 716	. . . . . . 7 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → 𝐴:ℕ0⟶ℂ)
88	52	ad2antlr 717	. . . . . . 7 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → 𝑘 ∈ ℕ0)
89	87, 88	ffvelrnd 6624	. . . . . 6 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → (𝐴‘𝑘) ∈ ℂ)
90	89	mul01d 10575	. . . . 5 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → ((𝐴‘𝑘) · 0) = 0)
91	86, 90	eqtrd 2814	. . . 4 ⊢ ((((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) ∧ ¬ 𝑀 ≤ 𝑘) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = 0)
92		eldifsni 4553	. . . . . . 7 ⊢ (𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀}) → 𝑘 ≠ 𝑀)
93	92	adantl 475	. . . . . 6 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → 𝑘 ≠ 𝑀)
94	69, 66	letri3d 10518	. . . . . . 7 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (𝑘 = 𝑀 ↔ (𝑘 ≤ 𝑀 ∧ 𝑀 ≤ 𝑘)))
95	94	necon3abid 3005	. . . . . 6 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (𝑘 ≠ 𝑀 ↔ ¬ (𝑘 ≤ 𝑀 ∧ 𝑀 ≤ 𝑘)))
96	93, 95	mpbid 224	. . . . 5 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → ¬ (𝑘 ≤ 𝑀 ∧ 𝑀 ≤ 𝑘))
97		ianor 967	. . . . 5 ⊢ (¬ (𝑘 ≤ 𝑀 ∧ 𝑀 ≤ 𝑘) ↔ (¬ 𝑘 ≤ 𝑀 ∨ ¬ 𝑀 ≤ 𝑘))
98	96, 97	sylib 210	. . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → (¬ 𝑘 ≤ 𝑀 ∨ ¬ 𝑀 ≤ 𝑘))
99	65, 91, 98	mpjaodan 944	. . 3 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) ∧ 𝑘 ∈ ((0...(𝑀 + 𝑁)) ∖ {𝑀})) → ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = 0)
100		fzfid 13091	. . 3 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → (0...(𝑀 + 𝑁)) ∈ Fin)
101	26, 48, 99, 100	fsumss 14863	. 2 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → Σ𝑘 ∈ {𝑀} ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = Σ𝑘 ∈ (0...(𝑀 + 𝑁))((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))))
102	32	sumsn 14882	. . . 4 ⊢ ((𝑀 ∈ ℕ0 ∧ ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))) ∈ ℂ) → Σ𝑘 ∈ {𝑀} ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))))
103	15, 46, 102	syl2anc 579	. . 3 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → Σ𝑘 ∈ {𝑀} ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = ((𝐴‘𝑀) · (𝐵‘((𝑀 + 𝑁) − 𝑀))))
104	103, 38	eqtrd 2814	. 2 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → Σ𝑘 ∈ {𝑀} ((𝐴‘𝑘) · (𝐵‘((𝑀 + 𝑁) − 𝑘))) = ((𝐴‘𝑀) · (𝐵‘𝑁)))
105	12, 101, 104	3eqtr2d 2820	1 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ 𝐺 ∈ (Poly‘𝑆)) → ((coeff‘(𝐹 ∘𝑓 · 𝐺))‘(𝑀 + 𝑁)) = ((𝐴‘𝑀) · (𝐵‘𝑁)))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 198   ∧ wa 386   ∨ wo 836   = wceq 1601   ∈ wcel 2107   ≠ wne 2969   ∖ cdif 3789  {csn 4398   class class class wbr 4886  ⟶wf 6131  ‘cfv 6135  (class class class)co 6922   ∘_𝑓 cof 7172  ℂcc 10270  ℝcr 10271  0cc0 10272   + caddc 10275   · cmul 10277   ≤ cle 10412   − cmin 10606  ℕ₀cn0 11642  ℤcz 11728  ℤ_≥cuz 11992  ...cfz 12643  Σcsu 14824  Polycply 24377  coeffccoe 24379  degcdgr 24380

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1839  ax-4 1853  ax-5 1953  ax-6 2021  ax-7 2055  ax-8 2109  ax-9 2116  ax-10 2135  ax-11 2150  ax-12 2163  ax-13 2334  ax-ext 2754  ax-rep 5006  ax-sep 5017  ax-nul 5025  ax-pow 5077  ax-pr 5138  ax-un 7226  ax-inf2 8835  ax-cnex 10328  ax-resscn 10329  ax-1cn 10330  ax-icn 10331  ax-addcl 10332  ax-addrcl 10333  ax-mulcl 10334  ax-mulrcl 10335  ax-mulcom 10336  ax-addass 10337  ax-mulass 10338  ax-distr 10339  ax-i2m1 10340  ax-1ne0 10341  ax-1rid 10342  ax-rnegex 10343  ax-rrecex 10344  ax-cnre 10345  ax-pre-lttri 10346  ax-pre-lttrn 10347  ax-pre-ltadd 10348  ax-pre-mulgt0 10349  ax-pre-sup 10350  ax-addf 10351

This theorem depends on definitions:  df-bi 199  df-an 387  df-or 837  df-3or 1072  df-3an 1073  df-tru 1605  df-fal 1615  df-ex 1824  df-nf 1828  df-sb 2012  df-mo 2551  df-eu 2587  df-clab 2764  df-cleq 2770  df-clel 2774  df-nfc 2921  df-ne 2970  df-nel 3076  df-ral 3095  df-rex 3096  df-reu 3097  df-rmo 3098  df-rab 3099  df-v 3400  df-sbc 3653  df-csb 3752  df-dif 3795  df-un 3797  df-in 3799  df-ss 3806  df-pss 3808  df-nul 4142  df-if 4308  df-pw 4381  df-sn 4399  df-pr 4401  df-tp 4403  df-op 4405  df-uni 4672  df-int 4711  df-iun 4755  df-br 4887  df-opab 4949  df-mpt 4966  df-tr 4988  df-id 5261  df-eprel 5266  df-po 5274  df-so 5275  df-fr 5314  df-se 5315  df-we 5316  df-xp 5361  df-rel 5362  df-cnv 5363  df-co 5364  df-dm 5365  df-rn 5366  df-res 5367  df-ima 5368  df-pred 5933  df-ord 5979  df-on 5980  df-lim 5981  df-suc 5982  df-iota 6099  df-fun 6137  df-fn 6138  df-f 6139  df-f1 6140  df-fo 6141  df-f1o 6142  df-fv 6143  df-isom 6144  df-riota 6883  df-ov 6925  df-oprab 6926  df-mpt2 6927  df-of 7174  df-om 7344  df-1st 7445  df-2nd 7446  df-wrecs 7689  df-recs 7751  df-rdg 7789  df-1o 7843  df-oadd 7847  df-er 8026  df-map 8142  df-pm 8143  df-en 8242  df-dom 8243  df-sdom 8244  df-fin 8245  df-sup 8636  df-inf 8637  df-oi 8704  df-card 9098  df-pnf 10413  df-mnf 10414  df-xr 10415  df-ltxr 10416  df-le 10417  df-sub 10608  df-neg 10609  df-div 11033  df-nn 11375  df-2 11438  df-3 11439  df-n0 11643  df-z 11729  df-uz 11993  df-rp 12138  df-fz 12644  df-fzo 12785  df-fl 12912  df-seq 13120  df-exp 13179  df-hash 13436  df-cj 14246  df-re 14247  df-im 14248  df-sqrt 14382  df-abs 14383  df-clim 14627  df-rlim 14628  df-sum 14825  df-0p 23874  df-ply 24381  df-coe 24383  df-dgr 24384

This theorem is referenced by:  dgrmul  24463  plymul0or  24473  plydivlem4  24488  vieta1lem2  24503