theorem Th36:
    for X be Algebraic_Set of n,R holds X = Zero_(Ideal_X)
    proof
      let X be Algebraic_Set of n,R;
      consider I be Ideal of Polynom-Ring(n,R) such that
A1:   X = Zero_(I) by Def7;
      thus thesis by A1,Th34;
    end;
