public static interface AssociativeFormulaSupport.AssociativeSupportBridge
This interface defines a bridge between the AssociativeFormula
implementation like a concrete Disjunction and the AssociativeFormulaSupport
object which adds the implementation of the common functionality.
To provide as much common functionality as possible the AssociativeFormulaSupport
needs the bridge to create empty associative formulas, empty signatures and the
string representation for the operator symbol and the symbol that means
that the associative formula is empty.