Re: Homework 3 solutions posted online

You are right.. I proved the soundness of ~B => ~A (and in fact said so in the solutions).
But that is not what I asked for :-(

I have now modifed the online solutions.

rao

On 10/21/07, Kyle Luce <kyle.luce@asu.edu> wrote:

Hi, 

    I am confused by HW3 solution 1, part 2.

I got:

A => B  can be written as: ~A V B
~A => ~B  can be written as: A V ~B

A	B	~A V B	A V ~B
0	0	1	1
0	1	1	0
1	0	0	1
1	1	1	1

Am I wrong in my conversion of the implication ~A => ~B  to A V ~B or is it obvious where I went wrong?  Also, is it true that for soundness, every time A => B is true, that ~A => ~B should also be true? I just want to double check even my basic understanding.

On 10/21/07, Subbarao Kambhampati < rao@asu.edu > wrote:

Folks
 Homework 3 solutions are now posted online.

With this, you have all the solutions for all the homeworks that can help you with Wedneday's exam

Rao