Schematic Kleene algebra with tests (SKAT) supports the equational verification of flowchart scheme equivalence and captures simple while programs with assignment statements. We formalise SKAT in Isabelle/HOL, using the quotient type package to reason equationally in this algebra. We apply this formalisation to a complex flowchart transformation proof from the literature. We extend SKAT with as...

objectives: the aim of this study was to verify the treatment planning systems (tpss). the next aim was to validate imsure qa software for patient-specific qa in radiotherapy clinics.  material and methods: we used imsure qa software (standard imaging, v 3.5) for verification of 92 non-imrt plans (540 fields) in 10 radiotherapy clinics. to validate the imsure, dose measurement was performed in ...

We introduce abstraction in a probabilistic process algebra. The process algebra can be employed for specifying processes that exhibit both probabilistic and non-deterministic choices in their behaviours. Several rules and axioms are identified, allowing us to rewrite processes to less complex processes by removing redundant internal activity. Using these rules, we have successfully conducted a...

Well-designed interfaces use procedural and sensory cues to increase the salience of appropriate actions and intentions. However, empirical studies suggest that cognitive load can influence the strength of procedural and sensory cues. We formalise the relationship between salience and cognitive load revealed by empirical data. We add these rules to our abstract cognitive architecture developed ...

Event-condition-action (ECA) rules can specify decision processes and are widely used in reactive systems and active database systems. Applying formal verification techniques to guarantee properties of the designed ECA rules is essential to help the error-prone procedure of collecting and translating expert knowledge. However, while the nondeterministic and concurrent semantics of ECA rule exec...

Program transformation through the repeated application of simple rewrite rules is conducive to formal verification. In practice, program transformation oftentimes requires data to be moved throughout the program structure. This article explores the use of higher-order rewrite rules as the mechanism for accomplishing such data movement. The effectiveness of higher-order rewrite rules is demonst...

Runtime verification is analysis based on information extracted from a running system. Traditionally this involves reasoning about system states, for example using trace predicates. We have been investigating runtime verification for event-driven systems and in that context we propose a higher level of abstraction can be useful, namely reasoning at the level of user-perceived system events. And...