By listingthem, we decree and declare that all the faithful of both sexes mustregard them as condemned, reprobated, and rejected . . . We restrainall in the virtue of holy obedience and under the penalty of anautomatic major excommunication."
This seems to meet the requirements for an Ex Cathedra statements which are nicely summarized by Wikipedia:
https://en.wikipedia.org/wiki/Papal_infallibility#:~:text=the%20Roman%20Pontiff%20(the%20Pope,is%20outside%20the%20Catholic%20Church.
According to the teaching of the First Vatican Council
https://en.wikipedia.org/wiki/First_Vatican_Council and Catholic tradition, the conditions required for ex cathedra papal teaching are as follows:[12]
1 the Roman Pontiff (the Pope alone or with the College of Bishops)
https://en.wikipedia.org/wiki/College_of_Bishops2 speaks ex cathedra – that is, when (in the discharge of his office as shepherd and teacher of all Christians, and by virtue of his supreme apostolic authority)
https://en.wikipedia.org/wiki/Apostles_in_the_New_Testament he defines a doctrine:
A. concerning faith or morals, and
B. To be held by the whole Church.
The terminology of a definitive decree usually makes clear that this last condition is fulfilled, as through a formula such as "By the authority of Our Lord Jesus Christ and of the Blessed Apostles Peter and Paul, and by Our own authority, We declare, pronounce and define the doctrine […] to be revealed by God and as such to be firmly and immutably held by all the faithful," or through an accompanying anathema
https://en.wikipedia.org/wiki/Anathema stating that anyone who deliberately dissents
https://en.wikipedia.org/wiki/Dissent is outside the Catholic Church
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