Branching Time? Pruning Time!

Markus Latte, Martin Lange

Abstract: The full branching time logic ctl* is a well-known specification logic for reactive systems. Its satisfiability and model checking problems are well understood. However, it is still lacking a satisfactory sound and complete axiomatisation. The only proof system known for ctl* is Reynolds’ which comes with an intricate and long completeness proof and, most of all, uses rules that do not possess the subformula property.