Edit detail for Test revision 3 of 16

draw(5*sin(sqrt(x**2+y**2)) , x=-20..20 , y=-20..20);

   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) 
                                 Variable(x)
                               PositiveInteger

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

The Axiom Wiki does not support graphics directly but see OldGnuDraw? .