Fixed Points on Abstract Structures without the Equality Test

Margarita Korovina

Abstract


In this paper we present a study of definability properties of fixed points of effective operators on abstract structures without the equality test. In particular we prove that Gandy theorem holds for abstract structures. This provides a useful tool for dealing with recursive definitions using Sigma-formulas.

One of the applications of Gandy theorem in the case of the reals without the equality test is that it allows us to define universal Sigma-predicates. It leads to a topological characterisation of Sigma-relations on |R.

Full Text:

PDF


DOI: http://dx.doi.org/10.7146/brics.v9i26.21742
This website uses cookies to allow us to see how the site is used. The cookies cannot identify you or any content at your own computer.
OK


ISSN: 0909-0878 

Hosted by the State and University Library and Aarhus University Library