There's only 1 PRIM in control and that will be the one which is capable of computing the highest level of law.
If the MONITORING PRIM's decide that the output of PRIM in CONTROL is not in agree with their own output a message would set and PRIM in CONTROL role will be transferred to the next PRIM acc. the priority rules.
Is there not an inherent contradiction in the above two rules? If one PRIM can compute a higher law than the other two, surely they're quite likely to disagree with it??
(Excuse me for butting in - I fly somewhat simpler aircraft, and have only contributed to these threads three or four times on matters I know quite a bit about, but I have read all of all four of them in some detail as they've developed and, FWIW, I *am* a software engineer.)