std::string index(SHalfloop_const_handle l) const
{ if (verbose)  return (l==this->shalfloop()? "l0" : "l1");
  else return (l==this->shalfloop()? "0" : "1");
}
std::string index(SHalfloop_const_handle l) const
{ if (verbose)  return (l==this->shalfloop()? "l0" : "l1");
  else return (l==this->shalfloop()? "0" : "1");
}