Assistance requested with basic Maxima commands.

>>>>> "C" == C Frangos  writes:

    C> (1) Is it possible to synthesize a command to convert a string into a
    C>     valid expression, and then evaluate this using ev() ? The command
    C>     string(expr) does the opposite, converts an expression to a string.

Yes.  Something like

(defun $foo (string)
  (with-input-from-string (s string)
     (dbm-read s)))

will produce the same form as if you had typed the string input the
prompt. 

For this to all work, it needs to be made better, of course.  I didn't
actually try $foo from maxima, but just ran it in lisp.  So

(meval (third ($foo "sin(%pi/4): ")))

produces 

((MTIMES SIMP) ((RAT SIMP) 1 2) ((MEXPT SIMP) 2 ((RAT SIMP) 1 2)))

which is maxima's internal representation of sqrt(2)/2.

Ray