We examine the conditions under which we can keep simplicity or categoricity after adding a Skolem function to the theory. AMS classification: 03C45 , 03C50
We show that there exists a single minimal (Turing) degree b < 0 s.t. for all c.e. degrees 0 < a < 0 , 0 = a b. Since b is minimal this means that b complements all c.e....
The standard method of generating countable ordinals from uncountable ordinals can be replaced by a use of fixed point extractors available in the term calculus of Howard's s...
We point out a connection between reflection principles and generic large cardinals. One principle of pure reflection is introduced that is as strong as generic supercompactness of...