static NLABlock nla_parse(S text) {

  ret nla_parse(new NLABlock(text));

}

// fills and returns original object

static NLABlock nla_parse(NLABlock nla) {

  // parse into lines (or sentences, both is OK)

  if (nla.lines == null)

    nla.lines = sentencesOrLines(nla.text);

  // parse lines into fragments & define entities

  if (nla.parsedLines == null) {

    new Matches m;

    nla.entities = linkedHashSet();

    nla.parsedLines = new L;

    MapSO wordTree = wordTree();

    for (int i = 0; i < l(nla.lines); i++) {

      S s = nla.lines.get(i);

      NLABlock.Line line = nla.new Line;

      line.text = s;

      line.proposition = parseToFragmentsUsingWordTree(s, wordTree);

      // define entity & extend word tree

      if "There is...|there are..." {

        S name = m.rest();

        NLABlock.Entity e = new(name, line);

        if (matchX2("a...|an...", name, m))

          e.addSynonym("the " + m.rest());

        nla.entities.add(e);

        addToWordTree_multi(wordTree, e.synonyms, e);

      }

      nla.parsedLines.add(line);

    }

  }

  ret nla;

}