['they', 'discover', 'class', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'discover-84', "Synset('association.n.01')", 'EmptyParameter', 'EmptyParameter']
They soon discover, a class never encountered by Humans before.
<PRP> soon discover, a Synset('association.n.01') never encountered by Synset('primate.n.02') before.