reset

Clears whatever the rule remembers between replications. Does nothing by default.

Almost every rule here is a pure function of what it is given and needs this not at all. A rule that cycles, or that remembers who it chose last, is not -- and a rule carrying the end of one replication into the start of the next makes the second replication depend on the first, which is the one thing a replication may never do. The pool calls this as each replication begins, so a stateful rule is correct without its author having to remember.