Structural operational semantics for Kernel Andorra Prolog

Kernel Andorra Prolog is a framework for nondeterministic concurrent constraint logic programming languages. Many languages, such as Prolog, GHC, Parlog, and Atomic Herbrand, can be seen as instances of this framework, by adding specific constraint systems and constraint operations, and optionally by imposing further restrictions on the language and the control of the computation model. We systematically revisit the description in Haridi and Jarison [HJ90], adding the formal machinery which is necessary in order to completely formalize the control of the computation model. To this we add a formal description of the transformational semantics of Kernel Andorra Prolog. The semantics of Kernel Andorra Prolog is a set of or-trees which also captures infinite computations

Logic programming in the context of multiparadigm programming: the Oz experience

Oz is a multiparadigm language that supports logic programming as one of its major paradigms. A multiparadigm language is designed to support different programming paradigms (logic, functional, constraint, object-oriented, sequential, concurrent, etc.) with equal ease. This article has two goals: to give a tutorial of logic programming in Oz and to show how logic programming fits naturally into the wider context of multiparadigm programming. Our experience shows that there are two classes of problems, which we call algorithmic and search problems, for which logic programming can help formulate practical solutions. Algorithmic problems have known efficient algorithms. Search problems do not have known efficient algorithms but can be solved with search. The Oz support for logic programming targets these two problem classes specifically, using the concepts needed for each. This is in contrast to the Prolog approach, which targets both classes with one set of concepts, which results in less than optimal support for each class. To explain the essential difference between algorithmic and search programs, we define the Oz execution model. This model subsumes both concurrent logic programming (committed-choice-style) and search-based logic programming (Prolog-style). Instead of Horn clause syntax, Oz has a simple, fully compositional, higher-order syntax that accommodates the abilities of the language. We conclude with lessons learned from this work, a brief history of Oz, and many entry points into the Oz literature.Comment: 48 pages, to appear in the journal "Theory and Practice of Logic Programming

Exploiting the Synergy Between Gossiping and Structured Overlays

In this position paper we argue for exploiting the synergy between gossip-based algorithms and structured overlay networks (SON). These two strands of research have both aimed at building fault-tolerant, dynamic, self-managing, and large-scale distributed systems. Despite the common goals, the two areas have, however, been relatively isolated. We focus on three problem domains where there is an untapped potential of using gossiping combined with SONs. We argue for applying gossip-based membership for ring-based SONs---such as Chord and Bamboo---to make them handle partition mergers and loopy networks. We argue that small world SONs---such as Accordion and Mercury---are specifically well-suited for gossip-based membership management. The benefits would be better graph-theoretic properties. Finally, we argue that gossip-based algorithms could use the overlay constructed by SONs. For example, many unreliable broadcast algorithms for SONs could be augmented with anti-entropy protocols. Similarly, gossip-based aggregation could be used in SONs for network size estimation and load-balancing purposes

Drug-Eluting Bead, Irinotecan (DEBIRI) Therapy for Refractory Colorectal Liver Metastasis:A Systematic Review

Colorectal cancer and related mortality present a profound challenge in its management, even in this modern age. Even today, colorectal cancer-related deaths rank third in the world. Despite having multiple lines of chemotherapy, combined with radiotherapy and chemoembolization techniques, after or before surgical resection, the five-year survival rate is approximately 20%. Drug-eluting bead, irinotecan (DEBIRI) is a new technique that involves embolization of the feeding vessels to the tumour and delivering irinotecan for its chemotherapeutic effects. A significant amount of literature compares DEBIRI as an adjunct to various lines of chemotherapy. However, so far, not much data are available on DEBIRI as a singular treatment for those patients who have had multiple chemotherapies and still progressing and are not fit for liver resection. In this systematic review, we aim to highlight and bring together the results of those studies that focused on this specific patient group. A systematic search of the literature involving three large databases (published between January 2017 and July 2022), excluding languages other than English, was conducted to identify articles documenting patients who had disease progression despite chemotherapy and were not fit for surgical resection. The level of evidence and the quality check were assessed by two independent reviewers, and consensus with the senior author resolved disagreements. Out of seven studies that met the final criteria, we found a pooled cohort of 302 patients. The mean age of the patients was 61.2 years, ranging from 40.7 to 84 years. The most commonly used DEBIRI beads were M1 (70-150 um) and M2 (100-300 um), but two studies reported the use of 40 um as well. The total number of DEBIRI treatments performed in our pooled cohort was 904. The majority of the studies reported only G1/G2 toxicities among the patients, with maximal toxicity of G4 in a few selected patients. The median overall survival in our pooled cohort was 19.52 months. The median progression-free survival in our data was 5.76 months. Our systematic review concludes that DEBIRI is undoubtedly a useful treatment modality with an acceptable toxicity profile. This treatment offers a good overall survival benefit for refractory colorectal liver metastasis.</p

Independence in CLP Languages

Studying independence of goals has proven very useful in the context of logic programming. In particular, it has provided a formal basis for powerful automatic parallelization tools, since independence ensures that two goals may be evaluated in parallel while preserving correctness and eciency. We extend the concept of independence to constraint logic programs (CLP) and prove that it also ensures the correctness and eciency of the parallel evaluation of independent goals. Independence for CLP languages is more complex than for logic programming as search space preservation is necessary but no longer sucient for ensuring correctness and eciency. Two additional issues arise. The rst is that the cost of constraint solving may depend upon the order constraints are encountered. The second is the need to handle dynamic scheduling. We clarify these issues by proposing various types of search independence and constraint solver independence, and show how they can be combined to allow dierent optimizations, from parallelism to intelligent backtracking. Sucient conditions for independence which can be evaluated \a priori" at run-time are also proposed. Our study also yields new insights into independence in logic programming languages. In particular, we show that search space preservation is not only a sucient but also a necessary condition for ensuring correctness and eciency of parallel execution

Strategic directions in constraint programming

An abstract is not available