reserve a,b,c,h for Integer;
reserve k,m,n for Nat;
reserve i,j,z for Integer;
reserve p for Prime;

theorem
  multiples(0) = { 0 }
  proof
    set M = multiples(0);
    thus M c= {0}
    proof
      let x be object;
      assume x in M;
      then reconsider m = x as Multiple of 0 by Th61;
      0 divides m by Def15;
      hence thesis by TARSKI:def 1;
    end;
    let x be object;
    assume x in {0};
    then
A1: x = 0;
    0 is Multiple of 0 by Def15;
    hence thesis by A1;
  end;
