Prove2Me

Binomial coefficient identity #38483

Proved
WorkbookCorrected.plus_38483

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

arithmeticcorrectedelementaryworkbook

The elementary natural-number / rational identity

10∗(((11))∗((94)))=1∗(((101))∗((94)))10 * ((\binom{1}{1}) * (\binom{9}{4})) = 1 * ((\binom{10}{1}) * (\binom{9}{4}))

holds by direct arithmetic evaluation.

Formalization Note: This corrects Lean-Workbook record lean_workbook_plus_38483, 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_38483 (Apache-2.0).

Preamble
import Mathlib.Data.Nat.Choose.Basic
import Mathlib.Data.Rat.Defs
import Mathlib.Tactic.Ring
import Mathlib.Tactic.NormNum
Formal statement
theorem WorkbookCorrected.plus_38483 : (10:ℚ) * ((Nat.choose 1 1) * (Nat.choose 9 4)) = (1:ℚ) * ((Nat.choose 10 1) * (Nat.choose 9 4)) := by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook; record lean_workbook_plus_38483; Apache-2.0; corrects Open node edeeb5cb-58fd-4805-879b-a5576ffb0308

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