Subject: Re: intersection From: Erik Naggum <firstname.lastname@example.org> Date: 28 Jan 2004 15:02:26 +0000 Newsgroups: comp.lang.lisp Message-ID: <3284290946418800KL2065E@naggum.no> * Tuang | The Hyperspec says the following about intersection: If one of the lists contains duplicate elements, there may be duplication in the result. Sets implemented as lists are defined on the presence of members of the set in the list. It is strictly speaking an error to duplicate members of the set in the list representation, but this error is hard to detect inexpensively, so the rational course of action is to allow it with suitable hand-waving. The above is an instance of precisely such hand-waving. -- Erik Naggum | Oslo, Norway 2004-028 Act from reason, and failure makes you rethink and study harder. Act from faith, and failure makes you blame someone and push harder.