analog of fundef for Maxima functions defined in lisp file

On June   ,2011, Steve Haflich wrote:

  smh> There is a _standard_ interface for obtaining the soure for a 
function
  smh> See cl:function-lambda-epression.  However, there are no requirements 
on
  smh> this function.  The ANS allows this function always to return nil, 
and
  smh> indeed, a lambda function defined in a non-empty lexical evironment
  smh> cannot be represented portably by its plain source sexpr.
  smh>
  smh>   cl-user(10): (defun foo (x) (1+ x))
  smh>   foo
  smh>   cl-user(11): (function-lambda-expression #'foo)
  smh>   (lambda (x) (block foo (1+ x)))
  smh>   nil

Thanks for clarifying Allegro use, which works for me:
---------------------
CG-USER(1): (defun foo (x) (1+ x))
FOO
CG-USER(2): (foo 2)
3
CG-USER(3): (function-lambda-expression #'foo)
(LAMBDA (X) (BLOCK FOO (1+ X)))
NIL
FOO
--------------------------------
but CGL (via Maxima)  fails:

MAXIMA> (defun foo (x) (1+ x))
FOO
MAXIMA> (foo 2)
3
MAXIMA> (function-lambda-expression #'foo)
Maxima encountered a Lisp error:
 Error in EVAL [or a callee]: The function FUNCTION-LAMBDA-EXPRESSION is 
undefined.
Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.
--------------------
Ted Woollett