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Source labels openChecked July 26, 2026

Erdős ProblemsReal functions

Erdős Problem 1133

Let C>0C>0. There exists ϵ>0\epsilon>0 such that if nn is sufficiently large the following holds.

Mathematical statement

Let C>0C>0. There exists ϵ>0\epsilon>0 such that if nn is sufficiently large the following holds.

For any x1,,xn[1,1]x_1,\ldots,x_n\in [-1,1] there exist y1,,yn[1,1]y_1,\ldots,y_n\in [-1,1] such that, if PP is a polynomial of degree m<(1+ϵ)nm<(1+\epsilon)n with P(xi)=yiP(x_i)=y_i for at least (1ϵ)n(1-\epsilon)n many 1in1\leq i\leq n, then maxx[1,1]P(x)>C.\max_{x\in [-1,1]}\lvert P(x)\rvert >C.

Statement source: Erdős Problems statement material

Statement terms: Source-specific

Source-specific terms. Therefore does not assert reuse rights beyond attributed display.

Statement artifacts, not proofs

These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.

Pinned Lean formulation 1

erdos_1133

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_1133 :    answer(sorry)      C > (0 : ),  ε > (0 : ), ᶠ n :  in atTop,       x : Fin n  Icc (-1 : ) 1,         y : Fin n  Icc (-1 : ) 1,           P : Polynomial ,            (P.natDegree : ) < (1 + ε) * (n : )             ((Finset.univ.filter (fun i  P.eval (x i : ) = (y i : ))).card : )               (1 - ε) * (n : )              z  Icc (-1 : ) 1, |P.eval z| > C := by  sorry
Statement source
Formal Conjectures
Lean version
v4.27.0
Placeholder
Present; no proof artifact
Source evidence
Pinned source index
Fidelity review
Community formulation

References