eta.lf.KEYWORDS
- KEYWORDS = ['not', 'plur', 'past', 'pres', 'perf', 'prog', 'pasv', 'k', 'ka', 'ke', 'to', 'that', 'tht', 'fquan', 'nquan', 'nmod', 'amod', '*h', '*s', '*p', 'set-of', 'n+preds', 'np+preds', 'sub', 'rep', "'s", 'poss-by', 'adv-a', 'adv-e', 'adv-f', 'adv-s', '?', '!', '=', 'voc', 'voc-O', 'ds', 'ans-to', 'pu', 'cf', 'mod-a', 'mod-n', 'most-n', 'poss-ques', 'poss-ans']
a list of special keywords that are reserved for operators in ULF.