When would one negate the Sufficient side?

LeoFiro8

Me and a student were studying when we got a bit confused over when to negate the sufficient. Consider these two examples:
If you are a rabbit you are white.
R->W
No rabbit is white.
is it /R->W or R-> / W
I feel like the second one explains If you are a rabbit you are not white and the first one says no rabbit is white. Can somebody for the last time explain when the sufficient gets negated and when the necessary? something concrete to remember would be much appreciated, I know this might sounds basic but after awhile you just get confused...

harrismegan

If your statement is:

If Rabbit --> White
The contrapositive is /W ---> /R
If you are not white, then you are not a Rabbit.

If you're taking the negation...
If Rabbit ---> White

It would be:
Some Rabbits are Not White.

LSATPWNAGE

"No" is a negate necessary indicator, group 4. so, No rabbit is white = R-->/W or W-->/R
"If" is a sufficient indicator group 1. So, if you are a rabbit then you are white= R-->W or /W-->/R.

_FIDELIO_

No rabbit is white

Group 4-Negate Necessary

W---->/R
R----->/W

Now if you wanted this /R----->W

you could say "You are either a rabbit OR white"

which would be Group 3 Negate Sufficient.