Comparison to Related Works

• Explicit message reception --- difficult to deal with inheritance.
  • First-classing relevant facilities [Caromel] --- flexible but not so easy.
• Guards --- difficult to cope with history sensitivities.
  • Incrementally modifiable guard exp. [Frolund] --- same as above.
  • Guards + synchronization counters etc. --- hybrid.
• Accept/enabled sets --- weak on state partitioning.
  • Accept sets + daemon [Ishikawa] --- concept only.