Re: What isn't a tautology?

On 18 Jul 2005 15:11:54 -0700, Michael De <mikejde@xxxxxxxxx> said:
>> Unless you redefine "valid", in which case you are just changing the
>> subject, the schema in question is invalid.
>
> Nobody denied that. But a proviso can still make an invalid schema
> valid without changing the definition of 'valid' (unless you call
> allowing the empty domain in interpretations a redefinition of
> validity).

It is most definitely a redefinition of validity. You have altered the
class of models relative to which validity is defined and, even more to
the point, you've defined an *extensionally* different notion.

I take it this is not the "proviso" you had in mind for rendering the
schema in question valid, though.

.

Relevant Pages

  • Re: What isnt a tautology?
    ... the schema in question is invalid. ... But a proviso can still make an invalid schema ... > It is most definitely a redefinition of validity. ...
    (sci.logic)
  • Re: Is Validity Just a Hypothetical or Conditional Characteristic?
    ... I say it is that Q asserts some or all of what is asserted by P, ... this your schema trivially instantiated, ... analyze the particular composition of a formula ... view of the validity of a formula. ...
    (sci.logic)
  • Re: Is Validity Just a Hypothetical or Conditional Characteristic?
    ... we cannot instantiate your schema with atomic ... propositions. ... proof system, we can learn something about the ... validity of the counter example, ...
    (sci.logic)
  • How do I enforce a xsd?
    ... My users shall be able to upload xml documents to my web server. ... I will check the validity of the documents with my xsd schema. ... 1- How do they specify in the xml document that they are using my schema ...
    (microsoft.public.dotnet.xml)
  • Re: What isnt a tautology?
    ... Chris Menzel wrote: ... I am thinking up a subtle proviso to make it valid. ... > You mean you want to talk about a *different* schema? ...
    (sci.logic)