['they', 'split', 'investigate', 'EmptyParameter', 'EmptyParameter'] ['they', 'investigate', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
['<PRP>', 'split-23.2', 'investigate-35.4', 'EmptyParameter', 'EmptyParameter'] ['<PRP>', 'investigate-35.4', 'EmptyParameter', 'EmptyParameter', 'EmptyParameter']
They split up to investigate.
<PRP> split up to investigate.