A mass problem is a set of Turing oracles. If P and Q are mass problems, we say that P is weakly reducible to Q if every member of Q Turing computes a member of P. We say that P i...
We define the notion of ordinal computability by generalizing standard Turing computability on tapes of length to computations on tapes of arbitrary ordinal length. We show that a ...
This communication deals with positive model theory, a non first order model theoretic setting which preserves compactness at the cost of giving up negation. Positive model theory ...