OK It is clear that full fist order logic is not decidable. An the same for 2. order. In Erlangen one has implemented/interpreted CRM in DL. It is apparently so that if we introduce metaclasses then it is not possible to interpret/model CRM with metaclasses in DL. It may be so that CRM with metaclasses or some 2. order concept still can be interpreted as a decidable logic. This has to be checked formally.
I see that it is to strict as it stands now. We may weaken the sentence or remove it, I dont think it is essencial. Christian-Emil > Christian-Emil Ore wrote: >> Dear all, >> I attach a draft of a "about types". >> >> It is based on the new scopenote, the orignal text, Martin's new and the >> comments from Erlangen. >> >> Regards, >> Christian-Emil >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> Crm-sig mailing list >> [email protected] >> http://lists.ics.forth.gr/mailman/listinfo/crm-sig > Dear Christian-Emil, > > I like your text. > > I have tried to make the cases even more explicit. > > The Phrase: "Without this distinction second order concepts is introduced > and it is not possible to implement CRM as a decidable logical > system." is not correct. > > There are decidable subsets of second order logic. If we regard the issue > as relevant, we can > study in the near future what that means. SIS definitely implements second > order concepts > and is decidable. I have written the code myself .... long ago... > > Marco may know more details? > > Best, > > Martin > > -- > > -------------------------------------------------------------- > Dr. Martin Doerr | Vox:+30(2810)391625 | > Principle Researcher | Fax:+30(2810)391638 | > | Email: [email protected] | > | > Center for Cultural Informatics | > Information Systems Laboratory | > Institute of Computer Science | > Foundation for Research and Technology - Hellas (FORTH) | > | > Vassilika Vouton,P.O.Box1385,GR71110 Heraklion,Crete,Greece | > | > Web-site: http://www.ics.forth.gr/isl | > -------------------------------------------------------------- > >
