Thanks

is this correct negation too ;- to not be a jedi one must be a force user. /J -> F

Hi, count me in. thanks

Is this correct?

superset - cat (Monica is cat)

subset - fat cat (Racheal is fat cat)

if you are Racheal its sufficient that you are a cat but it is not necessary to be a fat cat to be in cat superset.

You have to be Monica, a cat (necessary) to be in fat cat subset but being just a cat does not mean you are a fat cat (sufficient)