On relative computability for curves
  We discuss a rational version of a conjecture of Matiyasevich, Davis, and Putnam on the relative decidability of the finiteness problem for Diophantine equations with respect to the existence problem. We formulate a suspicion that for rational solutions, the finiteness problem should be relatively decidable in contrast to the M-D-P conjecture for integer solutions. 
Minhyong Kim