Prove2Me

Subtracting two binomial coefficients

Proved
WorkbookSource.problem_22878

by wamlart · Sep 12, 2026 · Mathlib 0df444a (Lean v4.33.1)

lean-workbooksource-checked

Subtract (205)\binom{20}{5} from (245)\binom{24}{5}.

Source: InternLM Lean-Workbook, record lean_workbook_22878 (Apache-2.0). The complete source proposition and explicit variable declarations are preserved.

Preamble
import Mathlib
open Real Nat
Formal statement
theorem WorkbookSource.problem_22878 : (choose 24 5) - (choose 20 5) = 27000  :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_22878; Apache-2.0

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