Open In App

GATE | GATE-CS-2004 | Question 70

The following propositional statement is 
(P → (Q v R)) → ((P ^ Q) → R)

(A)



satisfiable but not valid
 

(B)



valid
 

(C)

a contradiction
 

(D)

none of the above
 


Answer: (A)
Explanation:

The correct option is A Satisfiable but not valid

(P→(Q∨R))→((P∧Q)→R

≡(P→Q+R)→(PQ→R)
≡[P′+Q+R]→[(PQ)′+R]
≡[P′+Q+R]→[P′+Q′+R]
≡(P′+Q+R)′+P′+Q′+R
≡PQ′R′+P′+Q′+R
≡Q′+Q′PR′+P′+R​
≡Q′+P′+R (by absorption law)

Which is a contingency (i.e. satisfiable but not valid).
 

Quiz of this Question
Please comment below if you find anything wrong in the above post

Article Tags :