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Exercise 2

1 Rewrite the condition in (1) into PDNF.

  • P isprime
  • R is2mod5
  • Q isgcd1

Form:

(P(x) ∧ ¬R(x)) ∨ ¬(P(x) ∨ ¬Q(x) ∨ R(x)) ∨ (¬P(x) ∧ ¬Q(x) ∧ R(x))

Into PDNF:

  • (P(x) ∧ ¬R(x)) ==(P(x) ∧ ¬R(x) ∧ Q(x)) ∨ (P(x) ∧ ¬R(x) ∧ ¬Q(x))
  • ¬(P(x) ∨ ¬Q(x) ∨ R(x)) == (¬P(x) ∧ Q(x) ∧ ¬R(x))
  • (¬P(x) ∧ ¬Q(x) ∧ R(x))

Solution: (P(x) ∧ ¬R(x) ∧ Q(x)) ∨ (P(x) ∧ ¬R(x) ∧ ¬Q(x)) ∨ (¬P(x) ∧ Q(x) ∧ ¬R(x)) ∨ (¬P(x) ∧ ¬Q(x) ∧ R(x))

truth table:

P(x) R(x) Q(x) out
T T T F
T T F F
T F T T
T F F T
F T T T
F T F F
F F T T
F F F F

2 How many minterms does the normalform contain? What does this mean for the corresponding truth table?

it has 4 minterms, this means that 4 out of the 8 rows need to be true.