Writing out the cat example helped me understand the word fluff a lot better:

A cat cannot exist without being a vertebrate, for there is no cat that is not a mammal, and a dog cannot exist without being a mammal.

A. There can be no vertebrate without being a mammal.

-Vertebrate → Mammal

B. There can be no mammal without being a vertebrate.

-Mammal → Vertebrate

C. One cannot be a dog without being a vertebrate.

-Dog → Vertebrate

D. Existing as a mammal is possible only if one is a cat.

-Mammal → Cat

E. There can be no vertebrate without being a cat.

-Vertebrate → Cat

@kaysh I think you slipped up in terms of negating the sufficient condition in your first example, "/PR --> /MJ". In this particular example, 'peer review will not occur' is technically already '/PR' without using the translation rules. To negate this clause, it would really translate to 'PR'. This would then change your translation to PR --> MJ.