What the hell is a tuple??
- An ordered pair. Dysprosia 03:23, 12 Dec 2003 (UTC)
No: All ordered pairs are tuples, but many tuples are not ordered pairs; some are ordered triples, etc. Michael Hardy 21:10, 12 Feb 2004 (UTC)
Is this correct?
"There is an algorithm that, when given an input — typically an integer or a tuple of integers or a sequence of characters — eventually halts if it is a member of S and otherwise runs forever." I've changed this sentence because all recursive sets are also recursively enumerable. Algorithms for RE sets are simply not guaranteed to halt if the input is not a member of the set. Also notice that the above sentence contradicts one of the examples.
- Both versions are correct. But perhaps your version is clearer. If I have an algorithm A for a recursive set S which terminates if an element e is not in S I can create a new algorithm A' which is the same as A but instead of terminating if e is not in S it goes into an infinite loop. Using this construction I can covert all terminating algorithms into non-terminating ones.
- P.S.If you post messages on talk pages please sign your message with ~~~~.MathMartin 19:19, 5 Apr 2005 (UTC)