PT12.S2.Game 3 - Lara, Mendel, and Natassia each buy

Webby_Songdo

In PT12.S2.Game 3, we have a rule that goes:

Mendel does not buy any kind of food that Nastassia buys.

JY, in his explanation video, drew the Lawgic as:

M --> /N

Why is it not /M --> N or N --> /M

Could you please help?

blanklaw

Sure! "Not" is group 4 logical indicator-- you pick one idea, negate it, and make it the necessary condition. So both of the ways to negate it would be M--> /N and N--> /M. Notice that these are just contrapositives of each other. You would NOT be able to stick the negation slash in the sufficient condition for this conditional statement. This is the "or but not both" negation (see the CC for more details on that...)