code: def add_child_ambig(child_ambig, child_unambig, ambig, unambig):
      
      for k in child_ambig:
          ambig.add(k)
          if k in unambig:
              del unambig[k]
  
      for k, v in child_unambig.items():
          new_keypair(k, v, ambig, unambig)
  
      return
docs: Add information about decodings of a child object
  
      :param child_ambig: ambiguous set from child
      :param child_unambig: unambiguous set from child
      :param ambig: set of keys storing ambig decodings
      :param unambig: dictionary storing unambiguous decodings
      :return: