After reading the entire document, I came upon the last paragraph
Wherefore, in order that all doubt may be removed regarding a matter of great importance, a matter which pertains to the Church’s divine constitution itself, in virtue of my ministry of confirming the brethren (cf. Lk 22:32) I declare that the Church has no authority whatsoever to confer priestly ordination on women and that this judgment is to be definitively held by all the Church’s faithful.
So I will assume that this staement fulfills the conditions of Papal infallibilty and as such, Popes have now spoken infallibly on three occasions. I had always thought it was only used twice.
Oh well, live and learn.