When you are proving a language is decidable, what are you effectively doing?

When you are proving a language is decidable开发者_运维问答, what are you effectively doing?

If you asking HOW is it done, I'm unsure, but I can check.

Basically, decidable is the language for which one can construct an algorithm (i.e. Turing machine) that will halt for ANY finite input (with accepting or rejecting the input). Undecidable is the language which is not decidable.

http://en.wikipedia.org/wiki/Recursive_language ... but more on the subject can easily be found. On this link there is only a quick mention of the term.

p.s. So, when constructing above mentioned algorithm, you are basically proving that language is decidable.