======================================================================= Vrije Universiteit Amsterdam ++ CWI Amsterdam ++ Utrecht University Three research positions in the NWO-sponsored project INFINITY: Infinite Objects, computation, modeling and reasoning ======================================================================= We are seeking three researchers at the level of Postdoc or Asssociate Professor (UD) for a period of two to three years. Candidates should have - Good knowledge of at least one and preferably more of the following fields: Term rewriting, Graph rewriting, Lambda calculus, Proof theory, Co-algebra, Co-induction, Logic and Automated Reasoning, Type theory - For a postdoc position: a (nearly) finished PhD in computer science, mathematics or logic - For a UD position: several additional years of research experience Starting date of the project is September 1st, 2005. Description of the project -------------------------- We consider infinite objects, such as streams, infinite trees, infinite terms and term graphs, both first order and higher order (with binders as in lambda calculus) or infinite communicating processes. Often these exhibit a regular or cyclic nature, but we are also interested in general infinite objects. A paradigm example is the coalgebra of infinite bitstreams. Several operators can be defined on these objects, such as the operator zip that zips two streams alternatingly into one. Defining ones = 1 : one zeros = 0 : zeros alt = 0 : 1 : alt we have equations such as zip(zeros, ones) = alt The equations holding in this coalgebra between these objects and their operators can be proved in three different ways: by coalgebraic techniques, by proof theory, and by infinitary term rewriting. These three methods have been developed up to now in relative isolation. This project investigates the relations between these approaches and aims to design methods such as new proof systems to deal with the infinite objects and their equations. Issues are well-definedness criteria, completeness of the methods, decidability and implementation. Thus the project combines for infinite objects the activities of computing, modeling, and reasoning. For detailed information see the full project proposal. It will be sent to you on request (email to rdv@cs.vu.nl, please mention "INFINITY" in the subject). The positions ------------- The project is headed by Prof. Dr. J.W. Klop and is a collaboration between the following Dutch research groups: - Vrije Universiteit Amsterdam, section "Theoretical Computer Science" contact: Dr. R.C. de Vrijer, rdv@cs.vu.nl, phone: +31 (0)20 5987770 - CWI Amsterdam, the group "Coordination languages" contact: Prof. Dr. J.J.M.M. Rutten, jan.rutten@cwi.nl - Utrecht University, the group "Theoretical Philosophy" contact: Dr. V. van Oostrom, Vincent.vanOostrom@phil.uu.nl The research will be embedded in the broader framework of the themes of the three participating research groups: formal methods, logic, term and graph rewriting, lambda calculus, coalgebraic methods, process algebra. At each institution there is one position available. Roughly the focus of the three positions varies as follows, more details to be found in the full proposal. - Vrije Universiteit: Proof theory, Infinitary term rewriting - CWI: Co-algebra, theory and applications - Utrecht University: Infinitary term rewriting and implementation using graph rewriting Applications ------------ The full project proposal will be sent to you on request (rdv@cs.vu.nl). Further enquiries can be made with the contact persons. You are invited to send your application by email to the contact person of the institution for which you want to apply. Deadline for applications is July 17, 2005. In case you learn of this job opportunity later than that date you may send an email to enquire whether it still makes sense to apply. Your application should consist of: - a cover letter - a curriculum vitae (including detailed information regarding your academic degrees, title and subject of your PhD-thesis, publications) - the names and addresses of two references If you are interested in more than one of the offered positions you should clearly indicate so and give your motivation. It is not necessary to write separate letters. Please include "INFINITY" in the subject of all your emails. 29-Jun-2005 13:02:09 -0300,1968;000000000001-0000001d