3.2.4. Unique Value Assignment Constraint

Try these first

1. 1.

   Define satisfiability in propositional logic.

   Hint

   Think about how truth values can affect logical expressions.

2. 2.

   What is a clause in CNF?

   Hint

   Remember the structure of CNF.

3. 3.

   What is the defining characteristic of a satisfiable proposition?

   • Has no truth assignments
   • Has at least one true assignment
   • Is always true

   Hint

   Think about definitions discussed.

4. 4.

   True or False: An unsatisfiable proposition has its negation as a tautology.

   • True
   • False

   Hint

   Recall the definitions of satisfiability.

5. 5.

   Given the proposition (p OR q) AND (¬p OR r), convert it to CNF and determine if it is satisfiable.

   Hint

   Consider different values for p, q, and r.

6. 6.

   Formulate a propositional statement for a simple Sudoku row that contains numbers 1, 2, and 3 in any order in columns 1, 2, and 3.

   Hint

   You need to ensure each number appears once in the row.