['they', 'attack', 'vessel', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'judgment-33.1-1', "Synset('instrumentality.n.03')", 'EmptyParameter', 'EmptyParameter']
Thus, on his recommendation, they are about to attack a vessel.
Thus, on <PRP> recommendation, <PRP> are about to attack a Synset('instrumentality.n.03').