Annonce

Download

annonce@lrde.epita.fr

August 2022

1 participants
2 discussions

Paper published in Information & Computation
by Uli Fahrenberg 05 Mar '23

05 Mar '23

The following paper has been published in Information & Computation: Posets With Interfaces as a Model for Concurrency Uli Fahrenberg, Christian Johansen, Georg Struth, Krzysztof Ziemiański We introduce posets with interfaces (iposets) and generalise their standard serial composition to a new gluing composition. In the partial order semantics of concurrency, interfaces and gluing allow modelling events that extend in time and across components. Alternativelytaking a decompositional view, interfaces allow cutting through events, while serial composition may only cut through edges of a poset. We show that iposets under gluing composition form a category, which generalises the monoid of posets under serial composition up to isomorphism. They form a 2-category when a subsumption order and a lax tensor in the form of a non-commutative parallel composition are added, which generalises the interchange monoids used for modelling series-parallel posets. We also study the gluing-parallel hierarchy of iposets, which generalises the standard series-parallel one. The class of gluing-parallel iposets contains that of series-parallel posets and the class of interval orders, which are well studied in concurrency theory, too. We also show that it is strictly contained in the class of all iposets by identifying several forbidden substructures. https://www.lrde.epita.fr/wiki/Publications/fahrenberg.22.iandc

1 2

article accepted: The 34th Symposium on Implementation and Application of Functional Languages
by Jim Newton (lrde) 16 Aug '22

16 Aug '22

Hi, I’m pleased to announce I’ve had a paper accepted for presentation at The 34th Symposium on Implementation and Application of Functional Languages (https://ifl22.github.io <https://ifl22.github.io/>). The paper is entitled: How to fold and color a map: Comparing Use-Cases of Tree-Fold vs Fold-Left. You may view the article here https://drive.google.com/file/d/1-65beERt9UylSmxgsWe-gcl3Hz8JvjzC/view?usp=… as it is not yet available on /lrde/doc, pending an IT issue. ABSTRACT In this article we examine some consequences of computation order of two different conceptual implementations of the fold function. We explore a set of performance- and accuracy-based experiments on two implementations of this function. In particular, we contrast the traditional fold-left implementation with another approach we refer to as tree-fold. It is often implicitly supposed that the binary operation in question has constant complexity. We explore several application areas which diverge from that assumption: rational arithmetic, floating-point arithmetic, and Binary Decisions Diagram construction. These are binary operations which degrade in performance as the fold iteration progresses. We show that these types of binary operations are good candidates for tree-fold. Kind regards Jim

1 0