Prove2Me

A factorial quotient for four steps

Proved
WorkbookSource.problem_50698

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

lean-workbooksource-checked

Number of paths from (0,0)(0,0) to (2,2)(2,2) : 4!/(2!∗2!)=64!/(2!*2!)=6

Source: InternLM Lean-Workbook, record lean_workbook_50698 (Apache-2.0). The complete source proposition and explicit variable declarations are preserved.

Preamble
import Mathlib
open Real Nat
Formal statement
theorem WorkbookSource.problem_50698 :
  Nat.factorial 4 / (Nat.factorial 2 * Nat.factorial 2) = 6  :=  by sorry
Source
https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, record lean_workbook_50698; Apache-2.0

View graph