['doctor', 'attempt', 'replace', 'EmptyParameter', 'EmptyParameter'] ['doctor', 'replace', 'it', 'EmptyParameter', 'EmptyParameter']
['<PERSON>5', 'try-61.1', 'substitute-13.6.2', 'EmptyParameter', 'EmptyParameter'] ['<PERSON>5', 'substitute-13.6.2', '<PRP>', 'EmptyParameter', 'EmptyParameter']
The Doctor attempts to replace it.
<PERSON>5 attempts to replace <PRP>.