yea i've noticed this too. for these earlier tests the first LR set feels way easier than the second

i think you got it. if unless is the beginning of the sentence, then yes its in the necessary.

A unless B aka "unless B, then A" =

if not A, then B

if not B, then A

B unless A aka "unless A, then B" =

if not B, then A

if not A, then B

see how they are the same?

only the sufficient condition is negated.