Commentary Inf XIII 72

A nearly perfect example of the rhetorical device chiasmus, this verse offered Dante an opportunity to exhibit his own mastery of Pier's intentionally difficult style. A perfect example would have all its constituent words in one order up to the midpoint, then repeated in the opposite order: 'We are all happy; happy all are we.' Pier's words are one word away from such 'perfection': 'ingiusto fece me contra me giusto.