}
private Set<ATermAppl> pruneExplanation(Triple pattern, Set<ATermAppl> explanation) {
Set<ATermAppl> prunedExplanation = new HashSet<ATermAppl>( explanation );
OntBuilder builder = new OntBuilder( kb );
KnowledgeBase copyKB;
PelletInfGraph copyGraph;
GraphLoader loader = new DefaultGraphLoader();
for( ATermAppl axiom : explanation ) {
prunedExplanation.remove( axiom );
copyKB = builder.build( prunedExplanation );
copyGraph = new PelletInfGraph( copyKB, (PelletReasoner) getReasoner(), loader );
if( !checkEntailment( copyGraph, pattern, false ) ) {
prunedExplanation.add( axiom );
}