We investigate the Church–Kalmár–Kreisel–Turing Theses concerning theoretical (necessary) limitations of future computers and of deductive sciences, in view of recent results of classical general relativity theory. We argue that (i) there are several distinguished Church–Turing-type Theses (not only one) and (ii) validity of some of these theses depend on the background physical theory we choos...

We study the complexity of deciding the equality of streams specified by systems of equations. There are several notions of stream models in the literature, each generating a different semantics of stream equality. We pinpoint the complexity of each of these notions in the arithmetical or analytical hierarchy. Their complexity ranges from low levels of the arithmetical hierarchy such as Π2 for ...

By the sometimes so-called Main Theorem of Recursive Analysis, every computable real function is necessarily continuous. Weihrauch and Zheng (TCS 2000), Brattka (MLQ2005), and Ziegler (ToCS 2006) have considered different relaxed notions of computability to cover also discontinuous functions. The present work compares and unifies these approaches. This is based on the concept of the jump of a r...

Introduction. According to a classical theorem of Post, the arithmetical sets may be obtained by the following construction : Step 0: "take" all the r.e. sets. Step n+1 : "add" all sets which are r.e. in sets "taken" at a previous stage. Moreover, this construction is intimately related to the Kleene arithmetical hierarchy, defined in terms of the number and quality of alternating numberquantif...

This paper introduces a decision model and framework for subcontractor selection and team formation in the built environment based on the triple-bottom-line economic/business, social and environmental aspects of sustainability. The model and decision framework aid the decision maker in forming a construction project team that can most benefit the overall goal of sustainability and compatibility...

In modern days as because there are multiple number of object-oriented software systems, it is a real challenge for everyone to choose single one system among so many and variety of alternatives. This is obviously a challenging task to find out the most appropriate software system. In this particular study Analytical Hierarchy Process (AHP) technique has been integrated with ISO 9126-1 and it h...