# On Turing Machines

1. May 18, 2017

### Gear300

It's been a while since I've done this, but the question spurred on. Is there any sort of named class that a machine that can decide on all Turing decidable problems would belong to?

Edit: Actually, I guess it would be Turing if you could program it to decide on a particular problem.

Last edited: May 18, 2017
2. May 21, 2017

### Staff: Mentor

Can you rephrase your question a bit?

Are you looking for actual code in Java or C++ or some generic algorithm?

3. May 21, 2017

### QuantumQuest

You must put your question in a more clear way as jedishrfu points out. A problem is decidable if there is an algorithm to answer it. As you may know an algorithm - formally speaking, is a TM that halts on all inputs whether accepted or not. So, effectively a decidable problem is equivalent to a recursive language. Now, just by guesswork, is your question about a UTM (Universal Turing Machine)? Because in this case the language $L_{u}$ of UTM is not recursive but recursively enumerable.