// See www.openfst.org for extensive documentation on this weighted
  // finite-state transducer library.
  //
  // Tests if two Far files contains isomorphic (key,fst) pairs.
  
  #include <string>
  
  #include <fst/flags.h>
  #include <fst/extensions/far/farscript.h>
  #include <fst/extensions/far/getters.h>
  
  DEFINE_string(begin_key, "",
                "First key to extract (def: first key in archive)");
  DEFINE_string(end_key, "", "Last key to extract (def: last key in archive)");
  DEFINE_double(delta, fst::kDelta, "Comparison/quantization delta");
  
  int main(int argc, char **argv) {
    namespace s = fst::script;
  
    string usage = "Compares the FSTs in two FST archives for isomorphism.";
    usage += "
  
    Usage:";
    usage += argv[0];
    usage += " in1.far in2.far
  ";
    usage += "  Flags: begin_key end_key";
  
    std::set_new_handler(FailedNewHandler);
    SET_FLAGS(usage.c_str(), &argc, &argv, true);
    s::ExpandArgs(argc, argv, &argc, &argv);
  
    if (argc != 3) {
      ShowUsage();
      return 1;
    }
  
    const auto arc_type = s::LoadArcTypeFromFar(argv[1]);
    if (arc_type.empty()) return 1;
  
    bool result = s::FarIsomorphic(argv[1], argv[2], arc_type,
                                   FLAGS_delta, FLAGS_begin_key, FLAGS_end_key);
  
    if (!result) VLOG(1) << "FARs are not isomorphic.";
  
    return result ? 0 : 2;
  }