reserve X for set;
reserve a,b,c,k,m,n for Nat;
reserve i for Integer;
reserve r for Real;
reserve p for Prime;

theorem
  645 divides 2|^645-2
  proof
A1: 645 = 3*5*43;
    3,5,43 are_mutually_coprime by PEPIN:41,59,NAT_4:32,INT_2:30;
    hence thesis by A1,Th41,Th42,Th43,Th12;
  end;
