Re: L0 translater and runner was finished (PureProlog Project)
Hoxide Ma <[email protected]>
| Newsgroups | gmane.comp.gnu.prolog.general |
|---|---|
| Message-ID | <[email protected]> |
You had gave some very useful information, then I found a lot of old discussions of this in the Google archives for comp.lang.prolog. Thank you very much for your help. --- Manuel Carro <[email protected]> 姝f锛 > > >> My question is: "What's a good way to do > occur-check?". > > Good question. Most Prolog systems do not > implment occur-check > unification (OCU) by default because of its cost. A > nave algorithm is > O(n^2) on the size of the terms to be unified. > There are however > algorithms which implement OCU in linear time; > (Martelli & Montanari, > 1977) is well known, but not the only one. The > usually admitted > reason why it is not more widely used is because it > has large > constants (i.e., its cost is T(n) = C1*n + C2, and > C1 and C2 are very > large, thus rendering it impractical). However, > some people reported > that in real programs a good implementation does not > slow > implementation that much; there is information at: > > http://www.cs.kuleuven.ac.be/~dtai/projects/ALP/newsletter/feb04/nav/nettalk.html#occurs > > On the other hand, it turns that that for some > applications one > does not want to have occurs check: see > http://arxiv.org/abs/cs.DS/0403028 , for example. > > -- > +---------------------------------------------------------------------------+ > |Manuel Carro --- Facultad de Informtica -- U. > Politcnica de Madrid (UPM) | > |mcarro_at_fi_dot_upm_dot_es --- Ph: +34-91336-7455 > --- FAX: +34-91336-7412 | > |http://clip.dia.fi.upm.es/~mcarro - > http://clip.dia.fi.upm.es/Software/Ciao| > ===== A student of Math in Soochow University in China. Intrested in Math, Python, Twisted, Prolog and .NET/MONO. _________________________________________________________ Do You Yahoo!? 150涓MP3锛甯ㄩラ充娈垮 http://music.yisou.com/ 缇コ搴灏芥锛缇俱冲惧峰 http://image.yisou.com 1G灏辨1000锛甸╂╁锛 http://cn.rd.yahoo.com/mail_cn/tag/1g/*http://cn.mail.yahoo.com/event/mail_1g/