Adds a predAnch to the temporalRelations layer
        @type my_predAnch: L{CpredicateAnchor}
        @param my_predAnch: predicateAnchor object

def add_predicateAnchor(self,my_predAnch):
        """
        Adds a predAnch to the temporalRelations layer
        @type my_predAnch: L{CpredicateAnchor}
        @param my_predAnch: predicateAnchor object
        """
        if self.temporalRelations_layer is None:
            self.temporalRelations_layer = CtemporalRelations()
            self.root.append(self.temporalRelations_layer.get_node())
        self.temporalRelations_layer.add_predicateAnchor(my_predAnch)