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functionp object => generalized-boolean
object—an object.
generalized-boolean—a generalized boolean.
Returns true if object is of type function; otherwise, returns false.
(functionp 'append) => false
(functionp #'append) => true
(functionp (symbol-function 'append)) => true
(flet ((f () 1)) (functionp #'f)) => true
(functionp (compile nil '(lambda () 259))) => true
(functionp nil) => false
(functionp 12) => false
(functionp '(lambda (x) (* x x))) => false
(functionp #'(lambda (x) (* x x))) => true
(functionp object) == (typep object 'function)