Congruence_by_Product_of_Moduli
Provedmodular-arithmeticnumber-theoryproofwiki
If a is congruent to b modulo m and modulo n, then a is congruent to b modulo lcm(m,n).
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem Congruence_by_Product_of_Moduli (a b m n : ℤ) (h : a ≡ b [ZMOD m]) (hn : a ≡ b [ZMOD n]) : a ≡ b [ZMOD (m * n / Int.gcd m n)] := by sorry
Source