Description: A Diophantine set is a
set of positive integers which is a projection of
the zero set of some polynomial. This definition somewhat awkwardly
mixes (via
mzPoly) and (to
define the zero sets);
the former could be avoided by considering coincidence sets of
polynomials at the cost of requiring two, and the second is driven by
consistency with our mu-recursive functions and the requirements of the
Davis-Putnam-Robinson-Matiyasevich proof. Both are avoidable at a
complexity cost. In particular, it is a consequence of 4sq 15668
that
implicitly restricting variables to adds no expressive power
over allowing them to range over . While this definition
stipulates a specific index set for the polynomials, there is actually
flexibility here, see eldioph2b 37326. (Contributed by Stefan O'Rear,
5-Oct-2014.) |