A pragmatic requirement (or pragma for short) is a type of meta-assertion on a rule. Pragmas state literals that must be true in order for the rule to be used in an inference. Like literals in the warrant of the rule (and unlike exceptions), pragmas are checked eagerly during inference. Pragmas are intended to provide a way to specify practical constraints governing the use of rules without having to sacrifice logical purity. Hence, a pragma can, but need not be, identical to a literal in the warrant of the rule. Pragmas are asserted using the predicate #$pragmaticRequirement. For more information, see the training module Logical Warrant vs. Pragmas.
