CathInfo.com

The 1917 Code of Canon Law was not a "new law".  It was merely the codification into one volume of the body of law that already existed in the Church.  cuм ex Apostolatus was the basis of Canon 188.4 which reads, in English, "Any office becomes vacant upon the fact and without any declaration by tacit resignation recognized by the law itself if a cleric publicly defects from the Catholic faith."  

I'm wondering why all the topics are coming up declaring them off-limits to sedevacantist arguments.  If anti-sedevacantist arguments were so compelling they would be able to stand for themselves.  The problem seems to be that sedevacantists make valid and good points while the anti-sedevacantists simply deny what they are seeing or say that they just can't accept the argument.

Asking questions that logically lead to the sedevacantist explanations while simultaneously declaring that such explanations are unwelcome is just like the modern biologists asking evolution/creationist questions but telling anyone who believes in creationism to keep out.

I can't say that I've ever seen an SSPX position on cuм ex Apostolatus.  But I have seen Bishop Fellay and Bishop Williamson solemnly declare that Benedict 16 and other bishops and cardinals teach and believe heretical doctrines but are still Catholics in good standing.  Thus, it appears that their position is that cuм ex Apostolatus and Saint Paul's Epistle to the Galations (compare Bishop Williamson's ELEISON  COMMENTS  CXCI  (March 12, 2001) : CASSOCKS  WEIGHED) are no longer in force.