On the correspondence between two classes of reduction systems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25754/1/0000314.pd

06291 Abstracts Collection -- The Role of Business Processes in Service-Oriented Architectures

The Dagstuhl seminar on emph{The Role of Business Processes in Service Oriented Architectures} (Seminar 06291) took place in July 2006 (16.07.2006-21.07.2006 to be precise). The seminar was attended by more than 40 experts from both academia and industry. Unlike most Dagstuhl seminars there was a high participation from industry (in particular from organizations developing software, e.g., IBM, SAP, Microsoft, Google, etc.). The focal point of the seminar was the marriage of business processes and service oriented architectures. This was reflected by the topics selected by the participants and their background

Full abstraction and limiting completeness in equational languages

This paper introduces a notion of full abstraction for equational languages under which each language has a unique fully abstract model which can also be characterized as the final object in a category of coherent computable models for the language. We describe two potentially different approaches to limiting completeness with respect to the fully abstract model--a traditional one based on normal forms and a new one based on the usable data content of terms. The former is used to prove limiting completeness for the language of regular systems [5] which includes as subsets and restrictions the equational parts of many other languages. The latter is used to define an abstract version of limiting completeness based on information systems [17] which allows us to derive a set of sufficient conditions for an equational language to be limiting complete for its fully abstract semantics. We discuss cases where the two notions coincide--as they do for regular systems--and cases where they do not. We believe that limiting completeness based on observable data content accurately reflects programming intuition. If this thesis is accepted, the appropriateness of the corresponding definition of approximant can be seen as a design principle to test the mutual suitability of the parameters defining a language.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27882/1/0000296.pd

Demand driven evaluation with equations

http://deepblue.lib.umich.edu/bitstream/2027.42/7924/5/bad3272.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/7924/4/bad3272.0001.001.tx

Modal Logic and Algebraic Specifications

The established approaches to the semantics of algebraic (equational) specifications are based on a category-theoretic perspective. When possible interpretations are viewed as a category, the extreme points---the initial and final algebras---present themselves as natural candidates for the canonical interpretation. However, neither choice provides a satisfactory solution for incomplete specifications of abstract data types---the initial algebra is not abstract enough and the final algebra often does not exist. We argue that in much of the work on algebraic specifications, the categorical viewpoint is simply a convenient technical device to semantically capture the modalities of necessity and possibility. It is actually more natural to consider the semantic problem from the perspective of modal logic, gathering possible interpretations into a Kripke model. When necessity and possibility are added as modal operators in the logical language, a new candidate for the canonical interpretati..