Re: What are schemata

Lars Marius Garshol (larsga@ifi.uio.no)
30 May 1998 20:42:07 +0200

* Tim Bray
|
| I kind of think that the thing people have in mind in this group
| when they say "schema" is "expressions of syntactic constraints
| which can be verified mechanically" or some such.

* James K. Tauber
|
| So is a schema a function that maps a document to a truth value?

I'd rather say that it is a definition of a set of documents, just as
a formal language is usually considered to be the set of sentences
that are well-formed in that language.

The software that verifies a document could be called "a function that
maps a document to a truth value", though. Mathematically, such
software would perform an "element of"-test on the set of documents
defined by the schema.

-- 
"These are, as I began, cumbersome ways / to kill a man. Simpler, direct, 
and much more neat / is to see that he is living somewhere in the middle /
of the twentieth century, and leave him there."     -- Edwin Brock


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