Prescribe predicate names and number and types of predicates' parameters

[kruegers]

As of now, predicates are just strings which lists of parameters are attached to. Anyone could just define their own predicates and give predicates new parameters etc. That was okay when the language was designed to quickly update . However, now that the language has become fairly stable, other goals like consistency and interoperability come more into focus. Please integrate the existing predicates into the language such that they also become available through content assist. If possible, do not integrate them into the grammar directly but through other means like a scope provider.

For this purpose, please conduct the following steps:

• Collect all predicates and their parameter types
• Implement a semantic check for these predicates.
• If possible, extract the predicates into a configuration file such that if one wishes to modify them or add new ones, one does not have to go back into the source code.