turing-complete

My son has been playing Little Big Planet 2 lately, and I noticed that the game editor allows AND gates, OR gates and NOT gates... Is it Turing complete? If so, can anyone recommend a source for learning to turn those primitives into something like a higher level conditional if? You need NOT and one of AND or OR to be able to do all binary logic. This is DeMorgan's Law , basically. However, this is not sufficient for Turing completeness. For that you also need random (or reducably equivalent) access (theoretically) infinite memory. Odds are, you'll be able to build a flip flop (a D flip flop

While reading some papers about the Turing completeness of recurrent neural nets (for example: Turing computability with neural nets, Hava T. Siegelmann and Eduardo D. Sontag, 1991), I got the feeling that the proof which was given there was not really that practical. For example the referenced paper needs a neural network which neuron activity must be of infinity exactness (to reliable represent any rational number). Other proofs need a neural network of infinite size. Clearly, that is not really that practical. But I started to wonder now if it does make sense at all to ask for Turing

As there are non-Turing complete languages out there, and given I didn't study Comp Sci at university, could someone explain something that a Turing-incomplete language (like Coq ) cannot do? Or is the completeness/incompleteness of no real practical interest (i.e. does it not make much difference in practice)? EDIT - I'm looking for an answer along the lines of you cannot build a hash table in a non-Turing complete language due to X , or something like that! First, I assume you've already heard of the Church-Turing thesis , which states that anything we call “computation” is something that

I know C++ template metaprogramming is Turing-complete. Does the same thing hold for preprocessor metaprogramming? No. The C++ preprocessor does not allow for unlimited state. You only have a finite number of on/off states, plus a include stack. This makes it a push-down automaton, not a turing machine (this ignores also the fact that preprocessor recursion is limited - but so is template recursion). However, if you bend your definitions a bit, this is possible by invoking the preprocessor multiple times - by allowing the preprocessor to generate a program which re-invokes the preprocessor,

There is a well-known fact that C++ templates are turing-complete , CSS is turing-complete (!) and that the C# overload resolution is NP-hard (even without generics). But is C# 4.0 (with co/contravariance, generics etc) compile-time turing complete ? Terrance Unlike templates in C++, generics in C# (and other .net lang) are a runtime generated feature. The compiler does do some checking as to verify the types use but, actual substitution happens at runtime. Same goes for Co and contravariance if I'm not mistaken as well as even the preprocessor directives . Lots of CLR magic. (At the

I just wanted to know if it is 100% possible, if my language is turing-complete, to write a program in it that prints itself out (of course not using a file reading function) So if the language just has the really necessary things in order to make it turing complete (I would prove that by translating Brainf*ck code to it), like output, variables, conditions and gotos (hell yes, gotos), can I try writing a quine in it? I'm also asking this because I'm not sure that a quine directly fits into Turing's law that the turing machine is capable of any computational task. I just want to know so I don

I've read "what-is-turing-complete" and the wikipedia page, but I'm less interested in a formal proof than in the practical implications of being Turing Complete. What I'm actually trying to decide is if the toy language I've just designed could be used as a general-purpose language. I know I can prove it is if I can write a Turing machine with it. But I don't want to go through that exercise until I'm fairly certain of success. Is there a minimum set of features without which Turing Completeness is impossible? Is there a set of features which virtually guarantees completeness? (My guess is