Prove2Me

Binomial coefficient identity #24733

Proved
WorkbookCorrected.plus_24733

by carlok · Sep 22, 2026 · Mathlib 0df444a (Lean v4.33.1)

arithmeticcorrectedelementaryworkbook

The elementary natural-number / rational identity

((116))−1−30−6=425(\binom{11}{6}) - 1 - 30 - 6 = 425

holds by direct arithmetic evaluation.

Formalization Note: This corrects Lean-Workbook record lean_workbook_plus_24733, 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_24733 (Apache-2.0).

Preamble
import Mathlib.Data.Nat.Choose.Basic
import Mathlib.Tactic.NormNum
Formal statement
theorem WorkbookCorrected.plus_24733 : (Nat.choose 11 6) - 1 - 30 - 6 = 425 := by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook; record lean_workbook_plus_24733; Apache-2.0; corrects Open node 17e57903-8962-4516-a1b1-ebcc7cb3fd67

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