 reserve R for commutative Ring;
 reserve A,B for non degenerated commutative Ring;
 reserve h for Function of A,B;
 reserve I0,I,I1,I2 for Ideal of A;
 reserve J,J1,J2 for proper Ideal of A;
 reserve p for prime Ideal of A;
 reserve S,S1 for non empty Subset of A;
 reserve E,E1,E2 for Subset of A;
 reserve a,b,f for Element of A;
 reserve n for Nat;
 reserve x,o,o1 for object;

theorem Lm6:
  multClSet(J,1.A) = {1.A}
  proof
    thus multClSet(J,1.A) c= {1.A}
    proof
      let x be object;
      assume x in multClSet(J,1.A); then
      consider n1 be Nat such that
A3:   x = (1.A)|^n1;
      x = 1.A by A3,Lm4;
      hence thesis by TARSKI:def 1;
    end;
    let x be object;
    assume x in {1.A}; then
    x = 1.A by TARSKI:def 1;
    hence thesis by C0SP1:def 4;
  end;
