Efficient Algorithm for Solving CNF/DNF Logic Problem with 9 Input Literals

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Homework Statement



There exists a function f. Assume that you are given f's CNF representation and f's DNF representation. The CNF representation has some number of clauses, and each clause has 3 literals. The DNF representation has some number of terms where each term has 3 literals. The CNF representation and the DNF representation correspond to the same function f. Now you are also given an input x = x_1,...,x_n. Give an algorithm for determining f(x) (either T or F) that only looks at 9 literals within x.


Homework Equations



Just the definition of CNF and DNF

The Attempt at a Solution



CNF is formatted such as: (A and B and C) or (D and E and F).
DNF is formatted such as: (A or B or C) and (D or E or F).

Somehow since you only need to look at one literal in a term of the CNF to know whether that term will be false, you can look also look at that same literal in the DNF to see if that term will be true in the DNF.

I am not sure what else to do.
 
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DrAlexMV said:

Homework Statement



There exists a function f. Assume that you are given f's CNF representation and f's DNF representation. The CNF representation has some number of clauses, and each clause has 3 literals. The DNF representation has some number of terms where each term has 3 literals. The CNF representation and the DNF representation correspond to the same function f. Now you are also given an input x = x_1,...,x_n. Give an algorithm for determining f(x) (either T or F) that only looks at 9 literals within x.


Homework Equations



Just the definition of CNF and DNF

The Attempt at a Solution



CNF is formatted such as: (A and B and C) or (D and E and F).
DNF is formatted such as: (A or B or C) and (D or E or F).

Somehow since you only need to look at one literal in a term of the CNF to know whether that term will be false, you can look also look at that same literal in the DNF to see if that term will be true in the DNF.

I am not sure what else to do.

What do CNF and DNF mean?
 
Disjunctive normal form and Conjunctive normal form
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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