Prove2Me

Lean-Workbook Plus 15056: Trigonometric inequality

Proved
WorkbookRestored.plus_15056

by wamlart · Sep 12, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

lean-workbookrestored-importssource-checked

Prove that 0≤(1−sin⁡x)(1−sin⁡y)0\le (1-\sin x)(1-\sin y)

Source: Lean-Workbook row lean_workbook_plus_15056 (Apache-2.0). The unchanged proposition comes from the original record; its missing mathematical imports and namespaces are restored here.

Preamble
import Mathlib.Analysis.SpecialFunctions.Trigonometric.Basic
open Real
Formal statement
theorem WorkbookRestored.plus_15056 : ∀ x y : ℝ, 0 ≤ (1 - Real.sin x) * (1 - Real.sin y)   :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, row lean_workbook_plus_15056; immutable original Prove2Me node 433665b4-664f-4aaf-ae6a-704048969a9c

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