- From: pat hayes <phayes@ai.uwf.edu>
- Date: Mon, 23 Jul 2001 19:10:26 -0700
- To: Graham Klyne <Graham.Klyne@Baltimore.com>
- Cc: w3c-rdfcore-wg@w3.org
>At 09:08 PM 7/16/01 +0100, I wrote: >>At 01:56 PM 7/16/01 -0500, Aaron Swartz wrote: >>>I'm unclear on the difference between model theory and abstract >>>syntax. Can someone clarify? >> >>I'll take a shot; I guess the real formal systems folks will put me right... >> >>I think they are clearly different, but related, issues. >> >>- Abstract syntax defines a language (i.e. a set of well formed >>formulae, or wff) in terms of some set of terminal symbols. Given >>a formula, it allows us to say whether or not it is a well formed >>sentence (instance) of the language. It also provides us with an >>annotation for the the structure of a wff that can be used as a >>reference point for defining semantics for the various allowed >>forms. In summary: abstract syntax is primarily about forms. > >On reflection, that's not quite right... I think it's closer to say >that an abstract syntax captures the essential forms of a language, >without necessarily providing detailed rules for recognition of >wffs. This group has decided to use N-triples as the basis for its >abstract syntax, in which case it does define a specific form of >wff, but I don't think this is necessarily true of all abstract >syntax. > >Although I've often heard the term used, and think I have a feel for >what it means, I don't believe I've ever seen a specific definition >of "abstract syntax". The term is due to John McCarthy who introduced it http://www-formal.stanford.edu/jmc/towards/towards.html in the context of giving semantics for programming languages. It is widely used in theoretical CS. See http://www-formal.stanford.edu/jmc/towards/node12.html for a very brief intro. Pat --------------------------------------------------------------------- (650)859 6569 w (650)494 3973 h (until September) phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Monday, 23 July 2001 22:10:20 UTC