Results 1  10
of
14
A General Framework for Automatic Termination Analysis of Logic Programs
, 2000
"... This paper describes a general framework for automatic termination analysis of logic programs, where we understand by "termination" the finiteness of the LDtree constructed for the program and a given query. A general property of mappings from a certain subset of the branches of an infinite LDtree ..."
Abstract

Cited by 41 (9 self)
 Add to MetaCart
This paper describes a general framework for automatic termination analysis of logic programs, where we understand by "termination" the finiteness of the LDtree constructed for the program and a given query. A general property of mappings from a certain subset of the branches of an infinite LDtree into a finite set is proved. From this result several termination theorems are derived, by using different finite sets. The first two are formulated for the predicate dependency and atom dependency graphs. Then a general result for the case of the querymapping pairs relevant to a program is proved (cf. [29,21]). The correctness of the TermiLog system described in [22] follows from it. In this system it is not possible to prove termination for programs involving arithmetic predicates, since the usual order for the integers is not wellfounded. A new method, which can be easily incorporated in TermiLog or similar systems, is presented, which makes it possible to prove termination for programs involving arithmetic predicates. It is based on combining a finite abstraction of the integers with the technique of the querymapping pairs, and is essentially capable of dividing a termination proof into several cases, such that a simple termination function suffices for each case. Finally several possible extensions are outlined. Key words termination of logic programs  abstract interpretation  constraints ? This research has been partially supported by grants from the Israel Science Foundation 2 Nachum Dershowitz et al. 1
Program analysis as constraint solving
 In PLDI
, 2008
"... A constraintbased approach to invariant generation in programs translates a program into constraints that are solved using offtheshelf constraint solvers to yield desired program invariants. In this paper we show how the constraintbased approach can be used to model a wide spectrum of program ana ..."
Abstract

Cited by 33 (11 self)
 Add to MetaCart
A constraintbased approach to invariant generation in programs translates a program into constraints that are solved using offtheshelf constraint solvers to yield desired program invariants. In this paper we show how the constraintbased approach can be used to model a wide spectrum of program analyses in an expressive domain containing disjunctions and conjunctions of linear inequalities. In particular, we show how to model the problem of contextsensitive interprocedural program verification. We also present the first constraintbased approach to weakest precondition and strongest postcondition inference. The constraints we generate are boolean combinations of quadratic inequalities over integer variables. We reduce these constraints to SAT formulae using bitvector modeling and use offtheshelf SAT solvers to solve them. Furthermore, we present interesting applications of the above analyses, namely bounds analysis and generation of mostgeneral counterexamples for both safety and termination properties. We also present encouraging preliminary experimental results demonstrating the feasibility of our technique on a variety of challenging examples.
The Early Search for Tractable Ways of Reasoning About Programs
 IEEE Annals of the History of Computing
, 2003
"... This paper traces the important steps in the history up to around 1990 of research on reasoning about programs. The main focus is on sequential imperative programs but some comments are made on concurrency. Initially, researchers focussed on ways of verifying that a program satisfies its specifi ..."
Abstract

Cited by 15 (2 self)
 Add to MetaCart
This paper traces the important steps in the history up to around 1990 of research on reasoning about programs. The main focus is on sequential imperative programs but some comments are made on concurrency. Initially, researchers focussed on ways of verifying that a program satisfies its specification (or that two programs were equivalent). Over time it became clear that post facto verification is only practical for small programs and attention turned to verification methods which support the development of programs; for larger programs it is necessary to exploit a notation of compositionality. Coping with concurrent algorithms is much more challenging  this and other extensions are considered briefly. The main thesis of this paper is that the idea of reasoning about programs has been around since they were first written; the search has been to find tractable methods.
Automatic modular abstractions for linear constraints, in: Principles of programming languages
 ACM
"... We propose a method for automatically generating abstract transformers for static analysis by abstract interpretation. The method focuses on linear constraints on programs operating on rational, real or floatingpoint variables and containing linear assignments and tests. In addition to loopfree co ..."
Abstract

Cited by 15 (5 self)
 Add to MetaCart
We propose a method for automatically generating abstract transformers for static analysis by abstract interpretation. The method focuses on linear constraints on programs operating on rational, real or floatingpoint variables and containing linear assignments and tests. In addition to loopfree code, the same method also applies for obtaining least fixed points as functions of the precondition, which permits the analysis of loops and recursive functions. Our algorithms are based on new quantifier elimination and symbolic manipulation techniques. Given the specification of an abstract domain, and a program block, our method automatically outputs an implementation of the corresponding abstract transformer. It is thus a form of program transformation. The motivation of our work is dataflow synchronous programming languages, used for building controlcommand embedded systems, but it also applies to imperative and functional programming. 1
M.: “Whale: An Interpolationbased Algorithm for Interprocedural Verification
 In: Proc. of VMCAI’12
"... Abstract. In software verification, Craig interpolation has proven to be a powerful technique for computing and refining abstractions. In this paper, we propose an interpolationbased software verification algorithm for checking safety properties of (possibly recursive) sequential programs. Our algo ..."
Abstract

Cited by 14 (2 self)
 Add to MetaCart
Abstract. In software verification, Craig interpolation has proven to be a powerful technique for computing and refining abstractions. In this paper, we propose an interpolationbased software verification algorithm for checking safety properties of (possibly recursive) sequential programs. Our algorithm, called Whale, produces interprocedural proofs of safety by exploiting interpolation for guessing function summaries by generalizing underapproximations (i.e., finite traces) of functions. We implemented our algorithm in LLVM and applied it to verifying properties of lowlevel code written for the pacemaker challenge. We show that our prototype implementation outperforms existing stateoftheart tools. 1
Textbook Examples of Recursion
 In Artificial Intelligence and Theory of Computation
, 1991
"... Abstract. We discuss properties of recursive schemas related to McCarthy’s “91 function” and to Takeuchi’s triple recursion. Several theorems are proposed as interesting candidates for machine verification, and some intriguing open questions are raised. ..."
Abstract

Cited by 10 (0 self)
 Add to MetaCart
Abstract. We discuss properties of recursive schemas related to McCarthy’s “91 function” and to Takeuchi’s triple recursion. Several theorems are proposed as interesting candidates for machine verification, and some intriguing open questions are raised.
On the Search for Tractable Ways of Reasoning about Programs
, 2001
"... This paper traces the important steps in the history up to around 1990 of research on reasoning about programs. The main focus is on sequential imperative programs but some comments are made on concurrency. Initially, researchers focussed on ways of verifying that a program satifies its specific ..."
Abstract

Cited by 9 (1 self)
 Add to MetaCart
This paper traces the important steps in the history up to around 1990 of research on reasoning about programs. The main focus is on sequential imperative programs but some comments are made on concurrency. Initially, researchers focussed on ways of verifying that a program satifies its specification (or that two programs were equivalent). Over time it has become clear that post facto verification is only practical for small programs and attention turned to verification methods which support the development of programs; for larger programs it is necesary to exploit a notion of composability.
Automatic modular abstractions for template numerical constraints
 Logical Methods in Computer Science
, 2010
"... We propose a method for automatically generating abstract transformers for static analysis by abstract interpretation. The method focuses on linear constraints on programs operating on rational, real or floatingpoint variables and containing linear assignments and tests. Given the specification of a ..."
Abstract

Cited by 8 (2 self)
 Add to MetaCart
We propose a method for automatically generating abstract transformers for static analysis by abstract interpretation. The method focuses on linear constraints on programs operating on rational, real or floatingpoint variables and containing linear assignments and tests. Given the specification of an abstract domain, and a program block, our method transformer. It is thus a form of program transformation. In addition to loopfree code, the same method also applies for obtaining least fixed points as functions of the precondition, which permits the analysis of loops and recursive functions. The motivation of our work is dataflow synchronous programming languages, used for building controlcommand embedded systems, but it also applies to imperative and functional programming. Our algorithms are based on quantifier elimination and symbolic manipulation techniques over linear arithmetic formulas. We also give less general results for nonlinear constraints and nonlinear program constructs. 1
Interprocedurally Analysing Linear Inequality Relations
"... Abstract. In this paper we present an alternative approach to interprocedurally inferring linear inequality relations. We propose an abstraction of the effects of procedures through convex sets of transition matrices. In the absence of conditional branching, this abstraction can be characterised pre ..."
Abstract

Cited by 7 (0 self)
 Add to MetaCart
Abstract. In this paper we present an alternative approach to interprocedurally inferring linear inequality relations. We propose an abstraction of the effects of procedures through convex sets of transition matrices. In the absence of conditional branching, this abstraction can be characterised precisely by means of the least solution of a constraint system. In order to handle conditionals, we introduce auxiliary variables and postpone checking them until after the procedure calls. In order to obtain an effective analysis, we approximate convex sets by means of polyhedra. Since our implementation of function composition uses the frame representation of polyhedra, we rely on the subclass of simplices to obtain an efficient implementation. Indeed, we show that for this abstraction the basic operations can be implemented in polynomial time. First practical experiments indicate that the resulting analysis is quite efficient and provides reasonably precise results. 1
SatisfiabilityBased Program REASONING AND PROGRAM SYNTHESIS
, 2010
"... Program reasoning consists of the tasks of automatically and statically verifying correctness and inferring properties of programs. Program synthesis is the task of automatically generating programs. Both program reasoning and synthesis are theoretically undecidable, but the results in this disserta ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
Program reasoning consists of the tasks of automatically and statically verifying correctness and inferring properties of programs. Program synthesis is the task of automatically generating programs. Both program reasoning and synthesis are theoretically undecidable, but the results in this dissertation show that they are practically tractable. We show that there is enough structure in programs written by human developers to make program reasoning feasible, and additionally we can leverage program reasoning technology for automatic program synthesis. This dissertation describes expressive and efficient techniques for program reasoning and program synthesis. Our techniques work by encoding the underlying inference tasks as solutions to satisfiability instances. A core ingredient in the reduction of these problems to finite satisfiability instances is the assumption of templates. Templates are userprovided hints about the structural form of the desired artifact, e.g., invariant, pre and postcondition templates for reasoning; or program templates for synthesis. We propose novel algorithms, parameterized by suitable templates, that reduce the inference of these artifacts to satisfiability. We show that fixedpoint computation—the key technical challenge in program reasoning— is encodable as SAT instances. We also show that program synthesis can be viewed as generalized