From: John Somerville
Subject: Re: Why is (round 2.5) = 2?
Date: Mon, 17 Apr 1995 00:00:00 +0000
Message-ID: <69049-798163598@mindlink.bc.ca>

This has been a standard for as long as I can remember, but it has nothing
to do with Lisp per se.  If you round in this fashion, you will avoid bias
in a collection or list of numbers.