Semantics and Termination of Simply-Moded Logic Programs with Dynamic Scheduling

Termination Analysis of General Logic Programs for Moded Queries: A Dynamic Approach

The termination problem of a logic program can be addressed in either a static or a dynamic way. A static approach performs termination analysis at compile time, while a dynamic approach characterizes and tests termination of a logic program by applying a loop checking technique. In this paper, we present a novel dynamic approach to termination analysis for general logic programs with moded queries. We address several interesting questions, including how to formulate an SLDNF-derivation for a moded query, how to characterize an infinite SLDNF-derivation with a moded query, and how to apply a l…

Properties of Input-Consuming Derivations

We study the properties of input-consuming derivations of moded logic programs. Input-consuming derivations can be used to model the behavior of logic programs using dynamic scheduling and employing constructs such as delay declarations. We consider the class of nicely-moded programs and queries. We show that for these programs a weak version of the well-known switching lemma holds also for input-consuming derivations. Furthermore, we show that, under suitable conditions, there exists an algebraic characterization of termination of input-consuming derivations.

通用逻辑程序的模块化终止证明研究

On Modular Termination Proofs of General Logic Programs

该研究提出一种基于可接受程序概念的模块化方法，可通过单独处理层级模块证明含否定的通用逻辑程序终止性，针对良模式、良类型程序给出验证技术与迭代证明法，能大幅简化证明。

Termination Prediction for General Logic Programs

We present a heuristic framework for attacking the undecidable termination problem of logic programs, as an alternative to current termination/non-termination proof approaches. We introduce an idea of termination prediction, which predicts termination of a logic program in case that neither a termination nor a non-termination proof is applicable. We establish a necessary and sufficient characterization of infinite (generalized) SLDNF-derivations with arbitrary (concrete or moded) queries, and develop an algorithm that predicts termination of general logic programs with arbitrary non-flounderin…

Automated Termination Proofs for Logic Programs by Term Rewriting

There are two kinds of approaches for termination analysis of logic programs: "transformational" and "direct" ones. Direct approaches prove termination directly on the basis of the logic program. Transformational approaches transform a logic program into a term rewrite system (TRS) and then analyze termination of the resulting TRS instead. Thus, transformational approaches make all methods previously developed for TRSs available for logic programs as well. However, the applicability of most existing transformations is quite restricted, as they can only be used for certain subclasses of logic p…

A Separation Logic to Verify Termination of Busy-Waiting for Abrupt Program Exit: Technical Report

Programs for multiprocessor machines commonly perform busy-waiting for synchronisation. In this paper, we make a first step towards proving termination of such programs. We approximate (i) arbitrary waitable events by abrupt program termination and (ii) busy-waiting for events by busy-waiting to be abruptly terminated. We propose a separation logic for modularly verifying termination (under fair scheduling) of programs where some threads eventually abruptly terminate the program, and other threads busy-wait for this to happen.