The relative strength of topological properties for event structures

The intention of the paper is to characterize and examine density and crossing properties of prime event structures. We show the coincidence of L-density and L-ciossing for this class of event structures. It has turned out that any configuration in an M-dense prime event structure is full (i.e., at least one successor (if it exists) for any event occuring in the configuration must also occur). The structural restrictions which guarantee M-density are determined.