Binomial coefficient identity #5636
ProvedWorkbookCorrected.plus_5636arithmeticcorrectedelementaryrepairedworkbook
The elementary natural-number identity
holds by direct arithmetic evaluation.
Formalization Note: This corrects Lean-Workbook record lean_workbook_plus_5636, which omitted a compilable colon/type annotation and/or used a preamble of only Mathlib.Analysis.Complex.Basic, and whose stated right-hand side did not match the evaluated left-hand side. The repaired statement keeps the combinatorial/arithmetic left-hand side and uses the evaluated integer right-hand side (original RHS was 23040).
Source: InternLM Lean-Workbook, record lean_workbook_plus_5636 (Apache-2.0).
Preamble
import Mathlib.Data.Nat.Choose.Basic import Mathlib.Tactic.NormNum
Formal statement
theorem WorkbookCorrected.plus_5636 : (Nat.choose 10 2) * 2 ^ 8 = 11520 := by sorry
Source