Editing Cycle 13/Ruleset (section)

== Loops ==
Loop priority is a strict weak order over rules, defined as follows:

A persistent rule has higher loop priority than an ephemeral rule.

Otherwise, a rule with lexicographically earlier title has higher loop priority than a rule with lexicographically later title.

Otherwise, two rules have the same loop priority.

Loop Instability is an integer, initially 0. Ephemeral rules can provide for the alteration of the value of Loop Instability.

At the end of each phase (immediately before the new phase begins), the following occur in order:

* Loop Instability is incremented by 1.
* If Loop Instability is not less than 9, the following occur in order:
** Time collapses, and the current loop is considered to end. Effects occurring at the end of a loop by other rules occur. These effects occur simultaneously, except that effects in rules with higher loop priority happen before effects in rules with lower loop priority, and effects provided for earlier in a rule's text happen before effects provided for later in that rule's text.
** All rules that are not persistent are simultaneously repealed. During this step, rules to the contrary notwithstanding, only rule changes provided for by persistent rules (including this one) can occur. Should the evaluation of this step result in new non-persistent rules being enacted, those rules are included in the repeal step and thereby repealed.
** All items that are not defined as persistent by the rules are removed from inventories.
** Loop Instability is set to 0.

When a new phase begins while no loop is ongoing, a new loop is considered to begin, and effects defined by the rules as occurring at the beginning of a loop occur. These effects occur simultaneously, except that effects in rules with higher loop priority happen before effects in rules with lower loop priority, and effects provided for earlier in a rule's text happen before effects provided for later in that rule's text.

Rules and items that are not persistent are "ephemeral".