[Axiom-mail] eval function

[George Papadimitriou]

I'm trying to do the following:

1) In the axiom command line, I enter a ponynomial: f:=-(37/84)*x^2 -  
(7/12)*x -1/42
2) Find the roots: x12:=radicalSolve(f,x)
3) Trying to evaluate the polynomial 12x^3 + 5x^2 + 11x + 16:
        g:=12*x^3 + 5*x^2 + 11*x + 16
        eval(f,x,x12.1)

Then I get the error:
   There are 15 exposed and 1 unexposed library operations named eval
      having 3 argument(s) but none was determined to be applicable.
      Use HyperDoc Browse, or issue
                              )display op eval
      to learn more about the available operations. Perhaps
      package-calling the operation or using coercions on the arguments
      will allow you to apply the operation.

   Cannot find a definition or applicable library operation named eval
      with argument type(s)
                             Polynomial Integer
                                 Variable x
                         Equation Expression Integer

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


Can somebody tell me how to convert the type of x12.1 to something  
that eval will do the work with?

thanks
G