static L<PairS> ai_matchAngleBracketPattern(L<S> tokPat, L<S> tokInput) {
  L<PairS> match = zipTwoListsToPairs_ifSameLength(tokPat, tokInput);
  if (match == null) null;
  ret antiFilter parsing_checkMatchPairUsingMechList(uniquify(dropTwinPairsIC(match)));
}