English
Let R be a domain and p ∈ R[x]. Let s be a finite set of scalars from R. If p(r) = 0 for all r ∈ s and natDegree(p) < card(s), then p = 0.
Русский
Пусть R — домен и p ∈ R[x]. Пусть s — конечный набор элементов из R. Если p(r) = 0 для всех r ∈ s и natDegree(p) < card(s), то p = 0.
LaTeX
$$$ p \in R[x],\; s \subseteq R,\; s \text{ finite},\; (\forall r \in s, \ p(r)=0),\; \operatorname{natDegree}(p) < |s| \Rightarrow p = 0.$$
Lean4
theorem eq_zero_of_natDegree_lt_card_of_eval_eq_zero' {R} [CommRing R] [IsDomain R] (p : R[X]) (s : Finset R)
(heval : ∀ i ∈ s, p.eval i = 0) (hcard : natDegree p < #s) : p = 0 :=
eq_zero_of_natDegree_lt_card_of_eval_eq_zero p Subtype.val_injective (fun i : s ↦ heval i i.prop)
(hcard.trans_eq (Fintype.card_coe s).symm)