A relational event graph is described with unpredicated rules relating events, connecting a product of n
sources and m
conditions to a single sink (also called the goal). The format is as follows:
Y :- X[1], X[2], ..., X[n], c[1], c[2], ..., c[m].
means "when all events X[1]..X[n]
have happened, and all conditions c[1]..c[m]
have been met, then the goal Y
will happen". Because the right hand side is a product, the arguments are commutative and associative, so that the rule makes no demands as to in what order the sources are called, or the conditions are evaluated.
The resulting graph is a directed hypergraph of the B-graph class, with each rule constituting a B-arc.