Elementary arithmetic identity #22403

Proved

WorkbookCorrected.plus_22403

by carlok · Sep 29, 2026 · Mathlib 0df444a (Lean v4.33.1)

arithmeticcorrectedelementaryworkbook

The elementary natural-number / rational identity

25 + 23 + 21 + 19 + 17 + 15 + 13 + 11 + 9 + 7 + 5 + 3 + 1 = 169

holds by direct arithmetic evaluation.

Formalization Note: This corrects Lean-Workbook record lean_workbook_plus_22403, which omitted a compilable colon/type annotation and/or used a preamble of only Mathlib.Analysis.Complex.Basic.

Source: InternLM Lean-Workbook, record lean_workbook_plus_22403 (Apache-2.0).

Preamble

import Mathlib.Tactic.NormNum

Formal statement

theorem WorkbookCorrected.plus_22403 : 25 + 23 + 21 + 19 + 17 + 15 + 13 + 11 + 9 + 7 + 5 + 3 + 1 = 169 := by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook; record lean_workbook_plus_22403; Apache-2.0; corrects Open node 2c69dd67-2e11-48f1-a673-766ff312d2f3

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