A strict chain above one

Proved

WorkbookSource.problem_20573

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

Observe that $y^2+1>y^2>y$ for $y>1$ .

Source: InternLM Lean-Workbook, record lean_workbook_20573 (Apache-2.0). The complete source proposition and explicit variable declarations are preserved.

Preamble

import Mathlib
open Real Nat

Formal statement

theorem WorkbookSource.problem_20573 (y : ℝ) (h₁ : 1 < y) : y^2 + 1 > y^2 ∧ y^2 > y  :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_20573; Apache-2.0

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