The search for information on the web is faced with several problems, which arise on the one hand from the vast number of available sources, and on the other hand from their heterogeneity. A promising approach is the use of multi-agent systems of information agents, which cooperatively solve advanced information-retrieval problems. This requires capabilities to address complex tasks, such as search and assessment of sources, query planning, information merging and fusion, dealing with incomplete information, and handling of inconsistency. In this paper, our interest is in the role which some methods from the field of declarative logic programming can play in the realization of reasoning capabilities for information agents. In particular, we are interested in how they can be used and further developed for the specific needs of this application domain. We review some existing systems and current projects, which address information-integration problems. We then focus on declarative knowledge-representation methods, and review and evaluate approaches from logic programming and nonmonotonic reasoning for information agents. We discuss advantages and drawbacks, and point out possible extensions and open issues.
Informatics Institute, University of Amsterdam（阿姆斯特丹大学信息学研究所）
Modelling, specifying and reasoning about complex systems requires to process in an integrated fashion declarative and procedural aspects of the target domain. The paper reports on an experiment conducted with a propositional version of Logic Programming Petri Nets (LPPNs), a notation extending Petri Nets with logic programming constructs. Two semantics are presented: a denotational semantics that fully maps the notation to ASP via Event Calculus; and a hybrid operational semantics that process separately the causal mechanisms via Petri nets, and the constraints associated to objects and to ev…
We introduce Deep Adaptive Semantic Logic (DASL), a novel framework for automating the generation of deep neural networks that incorporates user-provided formal knowledge to improve learning from data. We provide formal semantics that demonstrate that our knowledge representation captures all of first order logic and that finite sampling from infinite domains converges to correct truth values. DASL's representation improves on prior neural-symbolic work by avoiding vanishing gradients, allowing deeper logical structure, and enabling richer interactions between the knowledge and learning compon…
DLV是一个高效的逻辑编程和非单调推理（LPNMR）系统，具有先进的知识表示机制和经典关系数据库系统的接口。它的核心语言是具有完整性约束的答案集语义（Answer Set Semantics）下的析取数据库（无函数析取逻辑编程），包括默认和强（或显式）否定以及查询。还支持算术运算和各种内置谓词。此外，DLV有几个前端，即勇敢和谨慎的推理，溯因诊断，基于一致性的诊断，SQL 3的一个子集，使用动作语言进行规划，以及使用继承进行逻辑编程。
Design, development and implementation of a tool for construction of declarative functional descriptions of semantic web services based on WSMO methodology
Софийски Университет “Св. Климент Охридски”（索非亚大学圣·克利门特·奥赫里德斯基大学）；Институт по информационни технологии – БАН（保加利亚科学院信息技术研究所）
语义Web服务（SWS）是自包含的，自描述的，语义标记的软件资源，可以发布，发现，组合和执行在Web上以半自动的方式。它们是未来语义网的关键组成部分，在语义网中，联网的计算机程序同时成为信息的提供者和用户。这项工作的重点是开发一个全生命周期的软件工具集创建和维护语义Web服务（SWSs）的Web服务建模本体（WSMO）框架的基础上。基于WSMO的SWS的一个主要部分是服务能力--Web服务功能的声明性描述。Web服务建模语言（WSML）提供了一个正式的语法和语义的描述，这是基于不同的逻辑形式主义，即描述逻辑，一阶逻辑和逻辑编程。Web服务功能的WSML描述表示为一组复杂的逻辑表达式（公理）。我们开发了一个专门的用户友好的工具，用于构建和编辑基于WSMO的SWS功能。由于该工具的用户不是一阶逻辑专家，因此提出了一种用于约束和编辑公理的图形化方法。构造逻辑表达式的设计过程是本体驱动的，它尽可能地从逻辑语言的任何具体语法中抽象出来。我们提出了几种机制来保证所产生的逻辑表达式的语义一致性。该工具使用Eclipse for IDE和GEF（图形编辑框架）以Java实现可视化。
University of North Texas（北德克萨斯大学）；Topos Institute（Topos研究所）
The problem we want to solve is how to generate all theorems of a given size in the implicational fragment of propositional intuitionistic linear logic. We start by filtering for linearity the proof terms associated by our Prolog-based theorem prover for Implicational Intuitionistic Logic. This works, but using for each formula a PSPACE-complete algorithm limits it to very small formulas. We take a few walks back and forth over the bridge between proof terms and theorems, provided by the Curry-Howard isomorphism, and derive step-by-step an efficient algorithm requiring a low polynomial effort …
Sapienza University of Rome（罗马第一大学）；Free University of Bozen-Bolzano（博尔扎诺自由大学）
We propose Answer Set Programming (ASP) as an approach for modeling and solving problems from the area of Declarative Process Mining (DPM). We consider here three classical problems, namely, Log Generation, Conformance Checking, and Query Checking. These problems are addressed from both a control-flow and a data-aware perspective. The approach is based on the representation of process specifications as (finite-state) automata. Since these are strictly more expressive than the de facto DPM standard specification language DECLARE, more general specifications than those typical of DPM can be hand…
Since the first conference held in Marseille in 1982, ICLP has been the premier international event for presenting research in logic programming. Contributions are sought in all areas of logic programming, including but not restricted to: Foundations: Semantics, Formalisms, Nonmonotonic reasoning, Knowledge representation. Languages: Concurrency, Objects, Coordination, Mobility, Higher Order, Types, Modes, Assertions, Modules, Meta-programming, Logic-based domain-specific languages, Programming Techniques. Declarative programming: Declarative program development, Analysis, Type and mode infere…
QILP-0: Constructing Observational Declarative Twins of Quantum Circuits
Universidad Internacional de la Rioja UNIR（国际拉里奥哈大学（UNIR））；Nantes Université（南特大学）；École Centrale Nantes（南特中央理工学院）；CNRS（法国国家科学研究中心）；National Institute of Informatics（情报学研究所）；Universidad de Oviedo（奥维耶多大学）
Towards a Systematic Account of Different Semantics for Logic Programs
在[Hitzler and Wendt 2002，2005]中，已经提出了一种新的方法，该方法允许导出具有否定的逻辑程序的不同声明性语义的统一表征。这项工作的一个结果是，良好的基础语义可以正式理解为Fitting（或Kripke-Kleene）语义的分层版本。然而，导致这一结果的结构显示出某种不对称性，这是不容易理解的。我们将在这里研究这种情况，其结果是，我们将获得正常逻辑程序的不同语义之间的关系的连贯画面。
Answer set programming is a declarative logic programming paradigm geared towards solving difficult combinatorial search problems. While different logic programs can encode the same problem, their performance may vary significantly. It is not always easy to identify which version of the program performs the best. We present the system Predictor (and its algorithmic backend) for estimating the grounding size of programs, a metric that can influence a performance of a system processing a program. We evaluate the impact of Predictor when used as a guide for rewritings produced by the answer set p…
Department of Mathematics and Computer Science University of Calabria（卡利亚里大学数学与计算机科学系）
Answer Set Programming (ASP) is a declarative logic formalism that allows to encode computational problems via logic programs. Despite the declarative nature of the formalism, some advanced expertise is required, in general, for designing an ASP encoding that can be efficiently evaluated by an actual ASP system. A common way for trying to reduce the burden of manually tweaking an ASP program consists in automatically rewriting the input encoding according to suitable techniques, for producing alternative, yet semantically equivalent, ASP programs. However, rewriting does not always grant benef…
Universitat Politècnica de València（瓦伦西亚理工大学）；University of Miyazaki（宫崎大学）
Given one or two examples, humans are good at understanding how to solve a problem independently of its domain, because they are able to detect what the problem is and to choose the appropriate background knowledge according to the context. For instance, presented with the string "8/17/2017" to be transformed to "17th of August of 2017", humans will process this in two steps: (1) they recognise that it is a date and (2) they map the date to the 17th of August of 2017. Inductive Programming (IP) aims at learning declarative (functional or logic) programs from examples. Two key advantages of IP …
The Johns Hopkins Applied Physics Lab（约翰斯·霍普金斯应用物理实验室）
We present an overview of the design and first proof-of-concept implementation for AIDA, an autonomous intelligent developer agent that develops software from scratch. AIDA takes a software requirements specification and uses reasoning over a semantic knowledge graph to interpret the requirements, then designs and writes software to satisfy them. AIDA uses both declarative and procedural knowledge in the core domains of data, algorithms, and code, plus some general knowledge. The reasoning codebase uses this knowledge to identify needed components, then designs and builds the necessary informa…
There has recently been an increasing interest in declarative data analysis, where analytic tasks are specified using a logical language, and their implementation and optimisation are delegated to a general-purpose query engine. Existing declarative languages for data analysis can be formalised as variants of logic programming equipped with arithmetic function symbols and/or aggregation, and are typically undecidable. In prior work, the language of $\mathit{limit\ programs}$ was proposed, which is sufficiently powerful to capture many analysis tasks and has decidable entailment problem. Rules …
Answer set programming is a prominent declarative programming paradigm used in formulating combinatorial search problems and implementing different knowledge representation formalisms. Frequently, several related and yet substantially different answer set programs exist for a given problem. Sometimes these encodings may display significantly different performance. Uncovering precise formal links between these programs is often important and yet far from trivial. This paper presents formal results carefully relating a number of interesting program rewritings. It also provides the proof of corre…
"Simply Logical -- Intelligent Reasoning by Example" by Peter Flach was first published by John Wiley in 1994. It could be purchased as book-only or with a 3.5 inch diskette containing the SWI-Prolog programmes printed in the book (for various operating systems). In 2007 the copyright reverted back to the author at which point the book and programmes were made freely available online; the print version is no longer distributed through John Wiley publishers. In 2015, as a pilot, we ported most of the original book into an online, interactive website using SWI-Prolog's SWISH platform. Since then…
Towards a unified theory of logic programming semantics: Level mapping characterizations of selector generated models
目前，针对带否定的逻辑程序所创建的各种表达扩展和不同语义是多样的、异质的，并且缺乏全面的比较研究，从而以统一的方式描绘出众多的视角。然而，最近，新的方法已经提出，它允许一个得到不同的声明性语义的逻辑程序与否定的统一表征。在本文中，我们研究了其中两种方法之间的关系，即[Hitzler and Wendt 2005]的水平映射特征和[Schwarz 2004]的选择器生成模型。我们将表明，后者可以被捕获的手段，前者，从而支持声称，层次映射提供了一个非常灵活的框架，这是适用于非常dilibrium定义的语义。
We propose answer-set programs that specify and compute counterfactual interventions on entities that are input on a classification model. In relation to the outcome of the model, the resulting counterfactual entities serve as a basis for the definition and computation of causality-based explanation scores for the feature values in the entity under classification, namely "responsibility scores". The approach and the programs can be applied with black-box models, and also with models that can be specified as logic programs, such as rule-based classifiers. The main focus of this work is on the s…
