/**
* Optimizations specific to XQuery.
*/
public final static List<IAlgebraicRewriteRule> buildPathStepNormalizationRuleCollection() {
List<IAlgebraicRewriteRule> normalization = new LinkedList<IAlgebraicRewriteRule>();
normalization.add(new SetVariableIdContextRule());
// Remove unused functions.
normalization.add(new RemoveUnusedSortDistinctNodesRule());
normalization.add(new RemoveRedundantVariablesRule());
normalization.add(new RemoveUnusedAssignAndAggregateRule());