I don't mean to be pulling answers out of you, but I'm stuck. Any advice on the right direction would be appreciated. I have the following set $X$ ={$n$ where $n$ is a number of a turing machine $M$ that does not halt when given $n$ as input}
My gut instinct is that it's not. And that's because the question asks about the set of all x's that are not partially decidable. Recursively enumerable languages ARE partially decidable, so it can't be REL.
Is this correct? And is this sufficient reasoning?
Thanks.