Scieneer Common Lisp 1.3.9 online documentation function-lambda-expression fun [Function] Given a function, return three values:
A lambda expression that could be used to define the function, or nil if the definition isn't available.
nil if the function was definitely defined in a null lexical environment, and t otherwise.
Some object that "names" the function. Although this is allowed to be any object, SCL always returns a valid function name or a string.