title: Is this language decidable?
body: <p>I'm struggling with whether or not this is decidable: </p>
  
  <p>A = {x is an element of the set of Natural Numbers | for every y greater than x, 2y is the sum of two primes}</p>
  
  <p>I'm inclined to think that this is decidable given the fact that when fed into a Turing Machine, it will never reach an accept state and loop for infinity unless it rejects.  However, I also do know that for a language to be decidable, there must only exist an algorithm to decide it; we don't necessarily have to know how it's done.  With this, part of me think that it is decidable? Does anyone know how to prove either? </p>