• sleep seconds → nil

• seconds - a non-negative real.

Causes execution to cease and become dormant for approximately the seconds of real time indicated by seconds, whereupon execution is resumed.

(sleep 1) 

→

NIL



;;; Actually, since SLEEP is permitted to use approximate timing, this might not always
;;; yield true, but it will often enough that we felt it to be a productive example of the intent.
(let ((then (get-universal-time))
      (now (progn (sleep 10) (get-universal-time))))
  (>= (- now then) 10)) 

→

true

Causes processing to pause.

The granularity of the scheduler.

Should signal an error of type type-error if seconds is not a non-negative real.

None.

None.