7.3.3. Algorithm for Tautology Check

Try these first

1. 1.

   What defines a tautology?

   Hint

   Think about examples like 'p OR NOT p'.

2. 2.

   What does the negation of a proposition do?

   Hint

   If the original is true, what is its negation?

3. 3.

   Is 'p OR NOT p' a tautology?

   • True
   • False

   Hint

   Evaluate the truth values.

4. 4.

   What happens if the negation of a proposition is satisfiable?

   • The proposition is a tautology
   • The proposition is not a tautology
   • Indeterminate

   Hint

   Think about what satisfiability means.

5. 5.

   Prove that the compound proposition 'not(p AND q)' is equivalent to 'NOT p OR NOT q'.

   Hint

   Start from the negation and manipulate it with laws.

6. 6.

   Identify a real-world scenario where tautologies are critical.

   Hint

   Think in terms of technology and reliability.