1.1 Establishing language-defined types

A known definition table key must be created for each type required by the language definition, and the IsType property of each must be set to 1. Mystery defines two types of values: integers and truth values. Only integers are denotable (by instances of the basic symbol Number); both are expressible, with a truth value being the result of the comparison operator > or the conjunction AND. Here are appropriate PDL specifications for those two types (see The property definition language):

     intType  -> IsType={1}; /* Integer values */
     boolType -> IsType={1}; /* Truth values */