static L<S> isYes_yesses = litlist("y", "yes", "yeah", "y", "yup", "yo", "corect", "sure", "ok", "afirmative", "true", "t"); // << collapsed words, so "corect" means "correct"

static boolean isYes(S s) {
  ret isYes_yesses.contains(collapseWord(toLowerCase(get(parse3(s), 1))));
}