Linguists often distinguish work they characterize as descriptive from work they characterize as theoretical. Similarly, linguists often characterize certain work as atheoretical. This label is sometimes applied, not only to descriptive work on particular languages, but also occasionally to crosslinguistic typological work. I argue in this chapter that this way of talking represents a fundament...

this research is a new attempt in order to study the effect of evolution theory in the dimension of empirical ethics. in the contemporary area the evolutionary ethics is in the three branches: descriptive, prescriptive and meta-ethics. the descriptive evolutionary ethics tries to modify human’s ethical believes in the evolutionary aspect and achieves more share from two others part in this grou...

In this article we give a partial answer to an important open problem in descriptive set theory, the Decomposability Conjecture on Borel functions from an analytic subset of a Polish space into a separable metrizable space. Our techniques employ deep results from effective descriptive set theory and recursion theory. In fact it is essential to prove that several prominent results in recursion t...

The paper discusses some recent developments in analysis of decision making under risk and uncertainty. First we present the expected utility theory and the basic assumptions of rationality. Second we discuss the critique that has been directed towards the expected utility theory. Next we present the alternative theories: regret theory, prospect theory and theory of stochastic preference. Final...

There is a fascinating interplay and overlap between recursion theory and descriptive set theory. A particularly beautiful source of such interaction has been Martin’s conjecture on Turing invariant functions. This longstanding open problem in recursion theory has connected to many problems in descriptive set theory, particularly in the theory of countable Borel equivalence relations. In this p...

Abst rac t . We investigate here the descriptional and the computational complexity of parallel communicating grammar systems (PCGS). A new descriptional complexity measure the communication structure of the PCGS is introduced and related to the communication complexity (the number of communications). Several hierarchies resulting from these complexity measures and some relations between the me...

In this paper we study a large number of logics to define languages of unordered unranked trees and compare their expressive power. Generally speaking, the logics we consider stem from three non-disjoint areas: logics related to automata theory, logics discussed in descriptive complexity theory, and second-order logics. The basic logic from automata theory is monadic second-order logic. Two ext...

We introduce a topology on the space of all isomorphism types represented in a given class of countable models, and use this topology as an aid in classifying the isomorphism types. This mixes ideas from effective descriptive set theory and computable structure theory, extending concepts from the latter beyond computable structures to examine the isomorphism problem on arbitrary countable struc...