A major focus of research in computability theory in recent years has involved definability issues in degree structures. There has been much success in getting general results by coding methods that translate first or second order arithmetic into the structures. In this paper we concentrate on the issues of getting definitions of interesting, apparently external, relations on degrees that are o...

gibbs and martin build on durkheim’s view that the degree of social integration is inversely related to the rate of suicide. according to gibbs and martin, which is expressed in terms of five axioms, the rate of suicide is a function of the degree of status integration in a society. this theory has been extensively subjected to experimental studies, which have supported its axioms. most of thes...

Gödel’s work [Gö34] on undecidable theories and the subsequent formalisations of the notion of a recursive function ([Tu36], [Kl36] etc.) have led to an ever deepening understanding of the nature of the non-computable universe (which as Gödel himself showed, includes sets and functions of everyday significance). The nontrivial aspect of Church’s Thesis (any function not contained within one of ...

I am very honoured and pleased to participate in the commemoration of the 50 th anniversary of the founding of the CWI of the Dutch Foundation Mathematical Centre. The subject of my talk is concerned not with diierential equations but with something that is used all the time in various nonlinear analytic problems , namely degree theory. It seems particularly appropriate to speak on this subject...

The starting point of this paper is the recent important work of F. E. Browder, who extended degree theory to operators of monotone type. The degree function of Browder is generalized to maps of the form T+f+G , where T is maximal monotone, f is of class (S)+ bounded, and G{ •) is an u.s.c. compact multifunction. It is also generalized to maps of the form f+NG , with / of class (5)+ and 7VC the...