# Package org.eclipse.viatra.query.runtime.matchers.psystem.basicdeferred

- Class Summary
  Class | Description
  --- | ---
  AggregatorConstraint | The PSystem representation of an aggregation.
  BaseTypeSafeConstraint |
  Equality |
  ExportedParameter |
  ExpressionEvaluation |
  Inequality |
  NegativePatternCall |
  PatternCallBasedDeferred |
  PatternMatchCounter |
  RelationEvaluation | A constraint which prescribes the evaluation of custom Java logic that takes an arbitrary number of input relations and produces one output relation.
  TypeFilterConstraint | Represents a non-enumerable type constraint that asserts that values substituted for the given tuple of variables form a tuple that belongs to a (typically non-enumerable) extensional relation identified by an `IInputKey`.