lean_workbook_plus_24525

Proved

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

Let $a, b, c$ be positive real numbers which are all less than 1. Prove the following inequality:\na + b + c - abc < 2.\n1956 Tokyo Institute of Technology entrance exam

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_24525 (a b c : ℝ) (ha : 0 < a ∧ a < 1) (hb : 0 < b ∧ b < 1) (hc : 0 < c ∧ c < 1): a + b + c - a * b * c < 2   :=  by sorry

Source

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

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