isabelle/valid/mathd_numbertheory_301.thy (13 lines of code) (raw):
(*
Authors: Wenda Li
*)
theory mathd_numbertheory_301
imports Complex_Main "HOL-Computational_Algebra.Computational_Algebra"
"HOL-Number_Theory.Number_Theory"
begin
theorem mathd_numbertheory_301:
fixes j :: nat
assumes "j>0"
shows "(3 * (7 * j + 3)) mod 7 = 2"
sorry
end