Prove2Me

Binomial coefficient identity #6006

Proved
WorkbookCorrected.plus_6006

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

arithmeticcorrectedelementaryworkbook

The elementary natural-number / rational identity

((92))/((122))=6/11(\binom{9}{2})/(\binom{12}{2}) = 6/11

holds by direct arithmetic evaluation.

Formalization Note: This corrects Lean-Workbook record lean_workbook_plus_6006, 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_6006 (Apache-2.0).

Preamble
import Mathlib.Data.Nat.Choose.Basic
import Mathlib.Tactic.NormNum
Formal statement
theorem WorkbookCorrected.plus_6006 : (Nat.choose 9 2) * 11 = (Nat.choose 12 2) * 6 := by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook; record lean_workbook_plus_6006; Apache-2.0; corrects Open node 23cc12e5-561a-435f-8e6b-a0a7396b0b82

View graph