theorem Th107:
  Product mlt(R1,R2) = Product R1 * Product R2
proof
  i is Nat by TARSKI:1;
  hence Product (mlt(R1,R2)) = multreal.(multreal$$R1,multreal$$R2)
  by SETWOP_2:35
    .= Product R1 * Product R2 by BINOP_2:def 11;
end;
