Predicate grammar
We define a Predicate grammar that describes how Predicates can be combined to form more elaborate Predicates.
predicate -> orPredicate orPredicate -> andPredicate or orPredicate orPredicate -> andPredicate andPredicate -> simplePredicate and andPredicate andPredicate -> simplePredicate simplePredicate -> ( orPredicate ) simplePredicate -> notPredicate notPredicate -> not simplePredicate |
 | Terminals are displayed like so: terminal |
| Note that this context-free grammar defines a precedence on rules. In the preceeding grammar, and has a higher precedence than or. |
Using this grammar, it is possible to define fairly complex combinations of Predicates that can describe complex pre-conditions. This set of Predicates is evaluated to a single Predicate according to the grammar rules.