`BookProof.ChapterFiniteArithmeticPrior.truncMul_eq_mul` {B : ℕ} [NeZero B] (a b : Fin B) (h : (a : ℕ) * (b : ℕ) < B) : (((truncMul B).result a b : Fin B) : ℕ) = (a : ℕ) * (b : ℕ)
ProvedBookProof.ChapterFiniteArithmeticPrior.truncMul_eq_multheoremstimepiece
Prove the following Lean 4 theorem from ChapterFiniteArithmeticPrior.
BookProof.ChapterFiniteArithmeticPrior.truncMul_eq_mul {B : ℕ} [NeZero B] (a b : Fin B) (h : (a : ℕ) * (b : ℕ) < B) : (((truncMul B).result a b : Fin B) : ℕ) = (a : ℕ) * (b : ℕ)
Formalization note: Lean 4 identifier BookProof.ChapterFiniteArithmeticPrior.truncMul_eq_mul.
Preamble
-- Generated from ChapterFiniteArithmeticPrior.lean — theorem BookProof.ChapterFiniteArithmeticPrior.truncMul_eq_mul import Mathlib import Definitions.Def_ChapterFiniteArithmeticPrior open BookProof.ChapterFiniteArithmeticPrior
Formal statement
theorem BookProof.ChapterFiniteArithmeticPrior.truncMul_eq_mul {B : ℕ} [NeZero B] (a b : Fin B) (h : (a : ℕ) * (b : ℕ) < B) :
(((truncMul B).result a b : Fin B) : ℕ) = (a : ℕ) * (b : ℕ) := by sorry