lean_workbook_plus_58417

Proved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

Let $x,y,z,t \in [0;1]$ . Prove that $x(1-y) + y(1-z) + z(1-t) + t(1-x) \leq 2$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_58417 (x y z t : ℝ) (hx : x ∈ Set.Icc 0 1) (hy : y ∈ Set.Icc 0 1) (hz : z ∈ Set.Icc 0 1) (ht : t ∈ Set.Icc 0 1) : x * (1 - y) + y * (1 - z) + z * (1 - t) + t * (1 - x) ≤ 2   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook

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