Intractability Problem (reduction form 3SAT)



We are feeling experimental and want to create a new dish. There are
various ingredients we can choose from and we'd like to use as many of
them as possible, but
some ingredients don't go well with others. If there are n possible
ingredients (numbered 1
to n), we write down an n x n matrix giving the discord between any
pair of ingredients. This
discord is a real number between 0.0 and 1.0, where 0.0 means (they go
together perfectly) and 1.0 means (they really don't go together.)
Here's an example matrix when there are ve
possible ingredients.


1 2 3 4 5
1 0.0 0.4 0.2 0.9 1.0
2 0.4 0.0 0.1 1.0 0.2
3 0.2 0.1 0.0 0.8 0.5
4 0.9 1.0 0.8 0.0 0.2
5 1.0 0.2 0.5 0.2 0.0


In this case, ingredients 2 and 3 go together pretty well whereas 1
and 5 clash badly. Notice that this matrix is necessarily symmetric;
and that the diagonal entries are always 0:0. Any set of ingredients
incurs a penalty which is the sum of all discord values between pairs
of ingredients.For instance, the set of ingredients {1; 3; 5} incurs
a
penalty of 0.2+1.0+0.5 = 1.7. We want this penalty to be small.

EXPERIMENTAL CUISINE
Input: n, the number of ingredients to choose from; D, the nxn
"discord" matrix; some
number p >= 0
Output: The maximum number of ingredients we can choose with penalty
<= p.

How do we show that if EXPERIMENTAL CUISINE is solvable in polynomial
time, then so is 3SAT.
Any Help would be appriciated.

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