Showing papers by "Jacques Fleuriot published in 2017"

A Workflow-Driven Formal Methods Approach to the Generation of Structured Checklists for Intrahospital Patient Transfers

Abstract: Intrahospital transfers are a common but hazardous aspect of hospital care, with a large number of incidents posing a threat to patient safety. A growing body of work advocates the use of checklists for minimizing intrahospital transfer risk, but the majority of existing checklists are not guaranteed to be error-free and are difficult to adapt to different clinical settings or changing hospital policies. This paper details an approach that addresses these challenges through the employment of workflow technologies and formal methods for generating structured checklists. A three-phased methodology is proposed, where intrahospital transfer processes are first conceptualized, then rigorously composed into workflows that are mechanically verified, and finally, translated into a set of checklists that support hospital staff while maintaining the dependencies between different transfer tasks. A case study is presented, highlighting the feasibility of this approach, and the correctness and maintainability benefits brought by the logical underpinning of this methodology. A checklist evaluation is discussed, with promising results regarding their usefulness.

WorkflowFM: A Logic-Based Framework for Formal Process Specification and Composition

Abstract: We present a logic-based system for process specification and composition named WorkflowFM. It relies on an embedding of Classical Linear Logic and the so-called proofs-as-processes paradigm within the proof assistant HOL Light. This enables the specification of abstract processes as logical sequents and their composition via formal proof. The result is systematically translated to an executable workflow with formally verified consistency, rigorous resource accounting, and deadlock freedom. The 3-tiered server/client architecture of WorkflowFM allows multiple concurrent users to interact with the system through a purely diagrammatic interface, while the proof is performed automatically on the server.

A Step Towards the Standardisation of HIV Care Practices

Abstract: Recent improvements to HIV care at the NHS Lothian Board have concentrated on a re-mapping of the processes involved in their existing Integrated Care Pathway (ICP), in order to incorporate improvements identified during the ICP implementation and consider new advances in care. Our work aims to extend and enhance this mapping by formalising care workflows using our logic-based tool WorkflowFM. This paper presents our progress to date in terms of methodology and initial findings concerning actors, resources and workflows involved in the first 3 months of HIV care for the Chalmers Sexual Health Centre. We argue that the resulting models and analysis could address some of the difficulties faced by units providing HIV outpatient care.

Bootstrapping LCF Declarative Proofs.

Abstract: Suppose we have been sold on the idea that formalised proofs in an LCF system should resemble their written counterparts, and so consist of formulas that only provide signposts for a fully verified proof. To be practical, most of the fully elaborated verification must then be done by way of general purpose proof procedures. Now if these are the only procedures we implement outside the kernel of logical rules, what does the theorem prover look like? We give our account, working from scratch in the ProofPeer theorem prover, making observations about this new setting along the way.

Local Lexing

Abstract: We introduce a novel parsing concept called local lexing. It integrates the classically separated stages of lexing and parsing by allowing lexing to be dependent upon the parsing progress and by providing a simple mechanism for constraining lexical ambiguity. This makes it possible for language design to be composable not only at the level of context-free grammars, but also at the lexical level. It also makes it possible to include lightweight error-handling directly as part of the language specification instead of leaving it up to the implementation. We present a high-level algorithm for local lexing, which is an extension of Earley's algorithm. We have formally verified the correctness of our algorithm with respect to its local lexing semantics in Isabelle/HOL.

Development of workflow-based guidelines for the care of burns in Scotland

Abstract: Burn injuries are considered complex because they require a variety of treatments and continuous healing. Moreover, due to the relatively small number of burns patients per year in Scotland, clinicians may lack sufficient experience and familiarity with the care process, leading to errors and omissions. In this work, we captured the necessary knowledge for the first 24 hours of burns treatment for adult patients in the form of structured workflows. Our aim is to construct visual workflow guidelines that can be easily read and understood, irrespective of any workflow expertise, and can be used as a guide in every day care. Preliminary evaluation results from burns care clinicians in the Glasgow Royal Infirmary are positive and will guide our future work. We believe workflow models can be an effective methodology to document and share guidelines for patient care provided they are developed in close collaboration with clinical stakeholders.

Compiling Purely Functional Structured Programs.

Abstract: We present a marriage of functional and structured imperative programming that embeds in pure lambda calculus. We describe how we implement the core of this language in a monadic DSL which is structurally equivalent to our intended source language and which, when evaluated, generates pure lambda terms in continuation-passing-style.