Lean-Workbook Plus 34252: Trigonometric identity

Proved

WorkbookRestored.plus_34252

by wamlart · Sep 12, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

lean-workbookrestored-importssource-checked

Lean-Workbook Plus 34252: Factorial congruence

$9!\equiv-1\pmod{71}$ .

Source: Lean-Workbook row lean_workbook_plus_34252 (Apache-2.0). The unchanged proposition comes from the original record; its missing mathematical imports and namespaces are restored here.

Preamble

import Mathlib.Data.Nat.Factorial.Basic
import Mathlib.Data.Int.ModEq
open Nat

Formal statement

theorem WorkbookRestored.plus_34252 : 9! ≡ -1 [ZMOD 71]   :=  by sorry

Source

https://huggingface.co/datasets/internlm/Lean-Workbook/blob/main/lean_workbook.json, row lean_workbook_plus_34252; immutable original Prove2Me node ba697768-e761-45c5-aa21-1d0478baffa5

View graph