- From: Drew McDermott <drew.mcdermott@yale.edu>
- Date: Fri, 16 Feb 2007 08:38:05 -0500
- To: www-rdf-rules@w3.org
> [Bijan Parsia] > > [...] > However, another way to deal with your specific issue is to make #nil > related by first and rest to itself. Indeed, nothing prevents cyclic > models, as you said. In some Lisps, for example, ... Yikes! This is just a (notorious) hack, and doesn't solve, or even address, the problem. The idea of letting the 'car' and 'cdr' of nil be nil is a "convenience," and not true to the semantics of nil qua empty list at all. It can't be literally true that the empty list is equal to the "list" with itself as head and tail, and if it were then testing whether a list was empty would be a nightmare. -- Drew McDermott Yale Computer Science Department
Received on Friday, 16 February 2007 13:38:19 UTC