Rule Destructors

rule_kind: rule tok.

Returns the kind of the rule. Note that at present this is in the internal form of the rule name. There are also predicates of the form is_universe_intro_void that correctly translate from the internal names of rules and the names of the rule constructors (as listed above with ``is_'' prepended). There are also destructors for each of the rules that correspond to the constructor. The names are of the form ``destruct_universe_intro_void''.