simplenlg.aggregation

Class BackwardConjunctionReductionRule

java.lang.Object

simplenlg.aggregation.AggregationRule

simplenlg.aggregation.BackwardConjunctionReductionRule

public class BackwardConjunctionReductionRule
extends AggregationRule

Implementation of the backward conjunction reduction rule. Given two sentences s1 and s2, this rule elides any constituent in the right periphery of s1 which is form-identical to a constituent with the same function in s2, that is, the two constituents are essentially identical in their final, realised, form.

The current implementation is loosely based on the algorithm in Harbusch and Kempen (2009), which is described here: http://aclweb.org/anthology-new/W/W09/W09-0624.pdf

Implementation note: The current implementation only applies ellipsis to phrasal constituents (i.e. not to their component lexical items).

*

Note:: this rule can be used in conjunction with the ForwardConjunctionReductionRule in Aggregator.

Author:

Albert Gatt, University of Malta and University of Aberdeen

Field Summary

Fields inherited from class simplenlg.aggregation.AggregationRule

factory

Constructor Summary

Constructors

Constructor and Description
BackwardConjunctionReductionRule() Creates a new BackwardConjunctionReduction.

Method Summary

Modifier and Type	Method and Description
NLGElement	apply(NLGElement previous, NLGElement next) Applies backward conjunction reduction to two NLGElements e1 and e2, succeeding only if they are clauses (that is, e1.getCategory() == e2.getCategory == PhraseCategory.CLAUSE).

Methods inherited from class simplenlg.aggregation.AggregationRule

apply, apply, getFactory, setFactory

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BackwardConjunctionReductionRule

public BackwardConjunctionReductionRule()

Creates a new BackwardConjunctionReduction.

Method Detail

apply

public NLGElement apply(NLGElement previous,
                        NLGElement next)

Applies backward conjunction reduction to two NLGElements e1 and e2, succeeding only if they are clauses (that is, e1.getCategory() == e2.getCategory == PhraseCategory.CLAUSE).

Specified by:

apply in class AggregationRule

Parameters:

previous - the first phrase

next - the second phrase

Returns:

a coordinate phrase if aggregation is successful, null otherwise