Wrap a function definition with `deprecated' to indicate that it should
no longer be used. If the first element of body is a string, it will be used
as additional documentation in the deprecation message. Foo example,

(deprecated
“Use bar instead.”
(defun foo-1 (x)
(format t “~%FOO: ~A” x)))

Will generate the message:

; warning FOO-1 has been deprecated. Use bar instead.

at compile time whereever foo-1 is used.