['he', 'mention', 'EmptyParameter', 'day', 'EmptyParameter']
['<PRP>', 'say-37.7', 'EmptyParameter', "Synset('cosmic_time.n.01')", 'EmptyParameter']
He should have mentioned that earlier that day.
<PRP> should have mentioned that Synset('early.a.05') that Synset('cosmic_time.n.01').