- From: John Cowan <cowan@mercury.ccil.org>
- Date: Tue, 28 Jan 2014 14:24:47 -0500
- To: "Henry S. Thompson" <ht@inf.ed.ac.uk>
- Cc: Paul Grosso <paul@paulgrosso.name>, core <public-xml-core-wg@w3.org>, "C. M. Sperberg-McQueen" <cmsmcq@blackmesatech.com>, Tim Bray <twbray@google.com>, Jean Paoli <jeanpa@microsoft.com>
Henry S. Thompson scripsit: > "The present king of france is bald" > > is not true, but not that it's false, or untrue. Whereas I hold with Quine and others that presupposition-failure sentences are just false. But even waiving that, I cannot see that a definition of the form "g(x) is true if there exists a y and f(y,x) is true" involves a presupposition at all. For example, if I say "A man is a father of a daughter if he has children and at least one of his children is female" (which is parallel to the definition of "valid"), then do you conclude that if a particular man has no children, then he is neither a father-of-a-daughter nor a non-father-of-a-daughter? I sure don't. I also don't think that changing "if" to "iff" as Liam suggests will help here either: in definitions, we usually treat "if" as "iff" anyway. An object is a natural number if it is either zero or the successor of a natural number; we don't normally bother to add that nothing else is a natural number. > For me that case is the crux of the matter, and it asks a substantive > question. In practice neither rxp nor xmllint report an Element Valid > VC, when invoked on that document in validating mode---are they > to be labelled non-conforming as a result? A priori, yes. > I find rxp's warning message the most illuminating: > > Document has no DTD, validating abandoned I take that to mean that rxp has ceased to be a validating parser and is acting as a non-validating parser instead. While that may be a pragmatically reasonable thing to do, I think there should be some way to override it and force it to report whether a document is valid or not valid. > I note, against my preference, something I've always been perplexed by > (at least I'm consistent): There are only three possible categories > allowed for a test in the metadata of the XML Test Suite [3]: > valid > invalid > not-wf > and e.g. test p22pass1 in the NIST/OASIS part of the suite, which is > <doc/> > is categorised as 'invalid'. I think this is based on "invalid" = "not valid" synonymy. -- John Cowan cowan@ccil.org http://ccil.org/~cowan Heckler: "Go on, Al, tell 'em all you know. It won't take long." Al Smith: "I'll tell 'em all we *both* know. It won't take any longer."
Received on Tuesday, 28 January 2014 19:25:17 UTC