isabelle/valid/numbertheory_prmdvsneqnsqmodpeq0.thy (13 lines of code) (raw):

(* Authors: Wenda Li *) theory numbertheory_prmdvsneqnsqmodpeq0 imports Complex_Main "HOL-Computational_Algebra.Computational_Algebra" begin theorem numbertheory_prmdvsneqnsqmodpeq0: fixes n :: int and p :: nat assumes "prime p" shows "p dvd n \<longleftrightarrow> (n^2) mod p = 0" sorry end