Axiomatization, Declarative Semantics and Operational Semantics of Passive and Active Updates in Logic Databases

1995 ◽  
Vol 5 (1) ◽  
pp. 27-70 ◽  
Author(s):  
PAUL SPRUIT ◽  
ROEL WIERINGA ◽  
JOHN-JULES MEYER
Keyword(s):  
Operational Semantics ◽  
Declarative Semantics

scholarly journals Contextual Abductive Reasoning with Side-Effects

2014 ◽  
Vol 14 (4-5) ◽  
pp. 633-648 ◽  
Author(s):  
LUÍS MONIZ PEREIRA ◽  
EMMANUELLE-ANNA DIETZ ◽  
STEFFEN HÖLLDOBLER
Keyword(s):  
Side Effects ◽  
Side Effect ◽  
Contextual Information ◽  
Operational Semantics ◽  
Syllogistic Reasoning ◽  
Abductive Reasoning ◽  
Reasoning Task ◽  
Bias Effect ◽  
Declarative Semantics ◽  
Scope Of Application

AbstractThe belief bias effect is a phenomenon which occurs when we think that we judge an argument based on our reasoning, but are actually influenced by our beliefs and prior knowledge. Evans, Barston and Pollard carried out a psychological syllogistic reasoning task to prove this effect. Participants were asked whether they would accept or reject a given syllogism. We discuss one specific case which is commonly assumed to be believable but which is actually not logically valid. By introducing abnormalities, abduction and background knowledge, we adequately model this case under the weak completion semantics. Our formalization reveals new questions about possible extensions in abductive reasoning. For instance, observations and their explanations might include some relevant prior abductive contextual information concerning some side-effect or leading to a contestable or refutable side-effect. A weaker notion indicates the support of some relevant consequences by a prior abductive context. Yet another definition describes jointly supported relevant consequences, which captures the idea of two observations containing mutually supportive side-effects. Though motivated with and exemplified by the running psychology application, the various new general abductive context definitions are introduced here and given a declarative semantics for the first time, and have a much wider scope of application. Inspection points, a concept introduced by Pereira and Pinto, allows us to express these definitions syntactically and intertwine them into an operational semantics.

An Integrated Approach for the Enforcement of Contextual Permissions and Pre-Obligations

2012 ◽  
pp. 107-126
Author(s):  
Yehia Elrakaiby ◽  
Frédéric Cuppens ◽  
Nora Cuppens-Boulahia
Keyword(s):  
Predicate Logic ◽  
Operational Semantics ◽  
Integrated Approach ◽  
Eca Rules ◽  
Authorization Policy ◽  
Declarative Semantics ◽  
Access Request ◽  
Successful Fulfillment ◽  
Authorization Policies

Pre-obligations denote actions that may be required before access is granted. The successful fulfillment of pre-obligations leads to the authorization of the requested access. Pre-obligations enable a more flexible enforcement of authorization policies. This paper formalizes interactions between the obligation and authorization policy states when pre-obligations are supported and investigates their use in a practical scenario. The main advantage of the presented approach is that it gives pre-obligations both declarative semantics using predicate logic and operational semantics using Event-Condition-Action (ECA) rules. Furthermore, the presented framework enables policy designers to easily choose to evaluate any pre-obligation either (1) statically (an access request is denied if the pre-obligation has not been fulfilled); or (2) dynamically (users are given the possibility to fulfill the pre-obligation after the access request and before access is authorized).

scholarly journals (Co-)Inductive semantics for Constraint Handling Rules

2011 ◽  
Vol 11 (4-5) ◽  
pp. 593-609 ◽  
Author(s):  
RÉMY HAEMMERLÉ
Keyword(s):  
Operational Semantics ◽  
Transition System ◽  
Constraint Handling ◽  
Declarative Semantics ◽  
Fixpoint Semantics ◽  
Propagation Rules

AbstractIn this paper, we address the problem of defining a fixpoint semantics for Constraint Handling Rules (CHR) that captures the behavior of both simplification and propagation rules in a sound and complete way with respect to their declarative semantics. Firstly, we show that the logical reading of states with respect to a set of simplification rules can be characterized by a least fixpoint over the transition system generated by the abstract operational semantics of CHR. Similarly, we demonstrate that the logical reading of states with respect to a set of propagation rules can be characterized by the greatest fixpoint. Then, in order to take advantage of both types of rules without losing fixpoint characterization, we present a new operational semantics with persistent constraints.We finally establish that this semantics can be characterized by two nested fixpoints, and we show that the resulting language is an elegant framework to program using coinductive reasoning.

scholarly journals Putting logic-based distributed systems on stable grounds

2015 ◽  
Vol 16 (4) ◽  
pp. 378-417
Author(s):  
TOM J. AMELOOT ◽  
JAN VAN DEN BUSSCHE ◽  
WILLIAM R. MARCZAK ◽  
PETER ALVARO ◽  
JOSEPH M. HELLERSTEIN
Keyword(s):  
Distributed Systems ◽  
Operational Semantics ◽  
Asynchronous Communication ◽  
Stable Model ◽  
Model Based ◽  
Distributed Computations ◽  
Declarative Semantics

AbstractIn the Declarative Networking paradigm, Datalog-like languages are used to express distributed computations. Whereas recently formal operational semantics for these languages have been developed, a corresponding declarative semantics has been lacking so far. The challenge is to capture precisely the amount of nondeterminism that is inherent to distributed computations due to concurrency, networking delays, and asynchronous communication. This paper shows how a declarative, model-based semantics can be obtained by simply using the well-known stable model semantics for Datalog with negation. We show that the model-based semantics matches previously proposed formal operational semantics.

An Integrated Approach for the Enforcement of Contextual Permissions and Pre-Obligations

2011 ◽  
Vol 3 (2) ◽  
pp. 33-51
Author(s):  
Yehia Elrakaiby ◽  
Frédéric Cuppens ◽  
Nora Cuppens-Boulahia
Keyword(s):  
Predicate Logic ◽  
Operational Semantics ◽  
Integrated Approach ◽  
Eca Rules ◽  
Authorization Policy ◽  
Declarative Semantics ◽  
Access Request ◽  
Successful Fulfillment ◽  
Authorization Policies

Pre-obligations denote actions that may be required before access is granted. The successful fulfillment of pre-obligations leads to the authorization of the requested access. Pre-obligations enable a more flexible enforcement of authorization policies. This paper formalizes interactions between the obligation and authorization policy states when pre-obligations are supported and investigates their use in a practical scenario. The main advantage of the presented approach is that it gives pre-obligations both declarative semantics using predicate logic and operational semantics using Event-Condition-Action (ECA) rules. Furthermore, the presented framework enables policy designers to easily choose to evaluate any pre-obligation either (1) statically (an access request is denied if the pre-obligation has not been fulfilled); or (2) dynamically (users are given the possibility to fulfill the pre-obligation after the access request and before access is authorized).

scholarly journals A simple correctness proof for magic transformation

2011 ◽  
Vol 12 (6) ◽  
pp. 929-936
Author(s):  
WŁODZIMIERZ DRABENT
Keyword(s):  
Operational Semantics ◽  
Logic Programs ◽  
Formal Reasoning ◽  
Correctness Proof ◽  
Declarative Semantics ◽  
Proof Of Correctness

AbstractThe paper presents a simple and concise proof of correctness of the magic transformation. We believe that it may provide a useful example of formal reasoning about logic programs. The correctness property concerns the declarative semantics. The proof, however, refers to the operational semantics (LD-resolution) of the source programs. Its conciseness is due to applying a suitable proof method.

scholarly journals Flexible coinductive logic programming

2020 ◽  
Vol 20 (6) ◽  
pp. 818-833 ◽  
Author(s):  
FRANCESCO DAGNINO ◽  
DAVIDE ANCONA ◽  
ELENA ZUCCA
Keyword(s):  
Fixed Point ◽  
Logic Programming ◽  
Operational Semantics ◽  
Powerful Approach ◽  
Declarative Semantics ◽  
Sld Resolution ◽  
Recursive Definitions ◽  
Special Meaning

AbstractRecursive definitions of predicates are usually interpreted either inductively or coinductively. Recently, a more powerful approach has been proposed, called flexible coinduction, to express a variety of intermediate interpretations, necessary in some cases to get the correct meaning. We provide a detailed formal account of an extension of logic programming supporting flexible coinduction. Syntactically, programs are enriched by coclauses, clauses with a special meaning used to tune the interpretation of predicates. As usual, the declarative semantics can be expressed as a fixed point which, however, is not necessarily the least, nor the greatest one, but is determined by the coclauses. Correspondingly, the operational semantics is a combination of standard SLD resolution and coSLD resolution. We prove that the operational semantics is sound and complete with respect to declarative semantics restricted to finite comodels.

scholarly journals Specifying and Executing User Agents in an Environment of Reasoning and RESTful Systems Using the Guard-Stage-Milestone Approach

2021 ◽  
Author(s):  
Tobias Käfer ◽  
Benjamin Jochum ◽  
Nico Aßfalg ◽  
Leonard Nürnberg
Keyword(s):  
Linked Data ◽  
Operational Semantics ◽  
Workflow Management ◽  
Management Systems ◽  
Workflow Management Systems ◽  
The Web

AbstractFor Read-Write Linked Data, an environment of reasoning and RESTful interaction, we investigate the use of the Guard-Stage-Milestone approach for specifying and executing user agents. We present an ontology to specify user agents. Moreover, we give operational semantics to the ontology in a rule language that allows for executing user agents on Read-Write Linked Data. We evaluate our approach formally and regarding performance. Our work shows that despite different assumptions of this environment in contrast to the traditional environment of workflow management systems, the Guard-Stage-Milestone approach can be transferred and successfully applied on the web of Read-Write Linked Data.

scholarly journals Persistent Stochastic Non-Interference

2021 ◽  
Vol 181 (1) ◽  
pp. 1-35
Author(s):  
Jane Hillston ◽  
Andrea Marin ◽  
Carla Piazza ◽  
Sabina Rossi
Keyword(s):  
Process Algebra ◽  
Operational Semantics ◽  
Evaluation Process ◽  
Decision Algorithm ◽  
Secure Systems ◽  
Information Flow Security ◽  
Structural Operational Semantics ◽  
Timing Properties ◽  
Functional Point ◽  
Security Property

In this paper, we study an information flow security property for systems specified as terms of a quantitative Markovian process algebra, namely the Performance Evaluation Process Algebra (PEPA). We propose a quantitative extension of the Non-Interference property used to secure systems from the functional point view by assuming that the observers are able to measure also the timing properties of the system, e.g., the response time of certain actions or its throughput. We introduce the notion of Persistent Stochastic Non-Interference (PSNI) based on the idea that every state reachable by a process satisfies a basic Stochastic Non-Interference (SNI) property. The structural operational semantics of PEPA allows us to give two characterizations of PSNI: one based on a bisimulation-like equivalence relation inducing a lumping on the underlying Markov chain, and another one based on unwinding conditions which demand properties of individual actions. These two different characterizations naturally lead to efficient methods for the verification and construction of secure systems. A decision algorithm for PSNI is presented and an application of PSNI to a queueing system is discussed.

Sign in / Sign up

Export Citation Format

Share Document