The control constructs provided by Common Lisp often allow shorter and more understandable code than use of PROG and GO, as illustrated by the following version of LENGTH:

(DEFUN LENGTH (L)

  (LET ((COUNT 0))

    (DOLIST (ITEM L) (INCF COUNT))

    COUNT ))

INCF is a macro that increments a value. (INCF COUNT) expands into
(SETQ COUNT (1+ COUNT)).

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