['sure', 'come', 'EmptyParameter', 'it', 'upon'] ['they', 'come', 'EmptyParameter', 'it', 'upon']
["Synset('certain.a.04')", 'become-109.1-1', 'EmptyParameter', '<PRP>', 'upon'] ['<PRP>', 'become-109.1-1', 'EmptyParameter', '<PRP>', 'upon']
Sure enough, less than one hour later, they come upon it.
Synset('certain.a.04') enough, <DATE>6 later, <PRP> come upon <PRP>.