446 research outputs found
On the nature of symbolic execution
In this paper, we provide a formal definition of symbolic execution in terms of a symbolic transition system and prove its correctness with respect to an operational semantics which models the execution on concrete values. We first introduce such a formal model for a basic programming language with a statically fixed number of programming variables. This model is extended to a programming language with recursive procedures which are called by a call-by-value parameter mechanism. Finally, we show how to extend this latter model of symbolic execution to arrays and object-oriented languages which feature dynamically allocated variables
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Protocol for single-cell isolation and genome amplification of environmental microbial eukaryotes for genomic analysis
We describe environmental microbial eukaryotes (EMEs) sample collection, single-cell isolation, lysis, and genome amplification, followed by the rDNA amplification and OTU screening for recovery of high-quality species-specific genomes for de novo assembly. These protocols are part of our pipeline that also includes bioinformatic methods. The pipeline and its application on a wide range of phyla of different sample complexity are described in our complementary paper. In addition, this protocol describes optimized lysis, genome amplification, and OTU screening steps of the pipeline. For complete details on the use and execution of this protocol, please refer to Ciobanu et al. (2021)
The play's the thing
For very understandable reasons phenomenological approaches predominate in the field of sensory urbanism. This paper does not seek to add to that particular discourse. Rather it takes Rorty’s postmodernized Pragmatism as its starting point and develops a position on the role of multi-modal design representation in the design process as a means of admitting many voices and managing multidisciplinary collaboration.
This paper will interrogate some of the concepts underpinning the Sensory Urbanism project to help define the scope of interest in multi-modal representations. It will then explore a range of techniques and approaches developed by artists and designers during the past fifty years or so and comment on how they might inform the question of multi-modal representation. In conclusion I will argue that we should develop a heterogeneous tool kit that adopts, adapts and re-invents existing methods because this will better serve our purposes during the exploratory phase(s) of any design project that deals with complexity
Superposition as a logical glue
The typical mathematical language systematically exploits notational and
logical abuses whose resolution requires not just the knowledge of domain
specific notation and conventions, but not trivial skills in the given
mathematical discipline. A large part of this background knowledge is expressed
in form of equalities and isomorphisms, allowing mathematicians to freely move
between different incarnations of the same entity without even mentioning the
transformation. Providing ITP-systems with similar capabilities seems to be a
major way to improve their intelligence, and to ease the communication between
the user and the machine. The present paper discusses our experience of
integration of a superposition calculus within the Matita interactive prover,
providing in particular a very flexible, "smart" application tactic, and a
simple, innovative approach to automation.Comment: In Proceedings TYPES 2009, arXiv:1103.311
A foundation for runtime monitoring
Runtime Verification is a lightweight technique that complements other verification methods in an effort to ensure software correctness. The technique poses novel questions to software engineers: it is not easy to identify which specifications are amenable to runtime monitor-ing, nor is it clear which monitors effect the required runtime analysis correctly. This exposition targets a foundational understanding of these questions. Particularly, it considers an expressive specification logic (a syntactic variant of the modal μ-calculus) that is agnostic of the verification method used, together with an elemental framework providing an operational semantics for the runtime analysis performed by monitors. The correspondence between the property satisfactions in the logic on the one hand, and the verdicts reached by the monitors performing the analysis on the other, is a central theme of the study. Such a correspondence underpins the concept of monitorability, used to identify the subsets of the logic that can be adequately monitored for by RV. Another theme of the study is that of understanding what should be expected of a monitor in order for the verification process to be correct. We show how the monitor framework considered can constitute a basis whereby various notions of monitor correctness may be defined and investigated.peer-reviewe
A Foundation for Runtime Monitoring
Runtime Verification is a lightweight technique that complements other
verification methods in an effort to ensure software correctness.
The technique poses novel questions to software engineers: it is not easy to
identify which specifications are amenable to runtime monitoring, nor is it
clear which monitors effect the required runtime analysis correctly.
This exposition targets a foundational understanding of these questions.
Particularly, it considers an expressive specification logic (a syntactic
variant of the mmucalc) that is agnostic of the verification method used,
together with an elemental framework providing an operational semantics for the
runtime analysis performed by monitors.
The correspondence between the property satisfactions in the logic on the one
hand, and the verdicts reached by the monitors performing the analysis on the
other, is a central theme of the study.
Such a correspondence underpins the concept of monitorability, used to identify
the subsets of the logic that can be adequately monitored for by RV.
Another theme of the study is that of understanding what should be expected of a
monitor in order for the verification process to be correct.
We show how the monitor framework considered can constitute a basis whereby
various notions of monitor correctness may be defined and investigated
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