Refinement Sensitive Formal Semantics of State Machines With Persistent Choice

Harald Fecher, Michael Huth, Heiko Schmidt, Jens Schönborn
2009 Electronical Notes in Theoretical Computer Science  
Modeling languages usually support two kinds of nondeterminism, an external one for interactions of a system with its environment, and one that stems from under-specification as familiar in models of behavioral requirements. Both forms of nondeterminism are resolvable by composing a system with an environment model and by refining under-specified behavior (respectively). Modeling languages usually don't support nondeterminism that is persistent in that neither the composition with an
more » ... with an environment nor refinements of under-specification will resolve it. Persistent nondeterminism is used, e.g., for modeling faulty systems. We present a formal semantics for UML state machines enriched with an operator "persistent choice" that models persistent nondeterminism. This semantics is based on abstract models -µ-automata with a novel refinement relation -and a sound three-valued satisfaction relation for properties expressed in the µ-calculus.
doi:10.1016/j.entcs.2009.08.006 fatcat:7rdl2ll3zvdudjvmkvpfxsxvwa