Thus spake Russ Abbott circa 09/07/2009 12:46 PM: > I'm missing the connection between *undecidable *and what I'm asking for.I > don't want a property of these things; I want a generic name for them.
The point is that the validity of a statement (e.g. a program, down to the formal parameters in a method call) can be determined either by syntax or by execution. In the extreme, if the language is fully typed, we can determine the validity of every sentence at compile time. If it's fully dynamic, we have to actually execute each sentence in order to determine if it's a valid statement. Sentences in fully dynamic languages have to be executed in order to determine whether they're valid (i.e. all exceptions happen at runtime). It's not clear to me whether this is precisely the same as a sentence being decidable or undecidable; but the gist is very close. In the most extreme, an undecidable sentence is proven undecidable if its effective computation will never halt, right? -- glen e. p. ropella, 971-222-9095, http://agent-based-modeling.com ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
