Law School Discussion

"unless" contrapositive

"unless" contrapositive
« on: November 21, 2006, 08:13:30 AM »
can y'all help me when some of the not-so-straight-forward contrapositives? 
i forget how to do the following

A will not be chosen unless B is chosen (what is the contrapositive?)

If A is selected, B and C will be selected (is it if  ~B or `~C ---> ~A?)

thanks!

jer

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Re: "unless" contrapositive
« Reply #1 on: November 21, 2006, 08:20:32 AM »
do you have the lr bible?
that is the best source of info, well worth the investment

Re: "unless" contrapositive
« Reply #2 on: November 21, 2006, 08:26:48 AM »
can the ~b or ~c ---> ~a be broken down into

~b ---< ~a
~c---> ~a

i just want to make sure im reading it right.

and i do have the bible but i stupidly came home for thanksgiving and forgot to pack it.  maybe i'll re-purchase here in the home stretch.  thanks!

Re: "unless" contrapositive
« Reply #3 on: November 21, 2006, 08:31:17 AM »
awesome,thanks!
and one more follow up just to be sure i get it:

A will be chosen unless B is chosen =

~b ---> a yeah?

Re: "unless" contrapositive
« Reply #4 on: November 21, 2006, 08:33:15 AM »
THANK YOU!