(1) -> Dx: LODO(EXPR INT, f+->D(f,x)) := D();

u := operator 'u;

L := Dx + u(x);

L**2 = L*L

   There are no library operations named ** 
      Use HyperDoc Browse or issue
                                 )what op **
      to learn if there is any operation containing " ** " in its name.

   Cannot find a definition or applicable library operation named ** 
      with argument type(s) 
LinearOrdinaryDifferentialOperator(Expression(Integer),theMap(*1;anonymousFunction;0;initial;internal))
                               PositiveInteger

      Perhaps you should use "@" to indicate the required return type, 
      or "$" to specify which version of the function you need.

or

)cl co

   All user variables and function definitions have been cleared.
   All )browse facility databases have been cleared.
   Internally cached functions and constructors have been cleared.
   )clear completely is finished.
f: INT->INT:=x+->x+1

(1)

K := OREUP(x, INT, 1, f);

L := x::K+1;

L^2=L*L

(2)

Reason is, that exponentiation is not taken from Monoid, but from SUP.

Martin