static Cl<Pair<S, Set<S>>> dm_topDownParseToGroupings(S input, Cl<S> patterns) {
  replace GroupingAndPatterns with Pair<S, Set<S>>.
  
  S parser = dm_makeModule("#1027108/TopDownParsing");
  Cl<GroupingAndPatterns> groupingsWithPatterns = cast dm_callWithImport(parser, 'parseToGroupingsWithUsedPatterns, input, +patterns));
  ret groupingsWithPatterns;
}