Discussion Forum
Que.  Define the connective * for the Boolean variables X and Y as: X * Y = XY + X' Y'. Let Z = X * Y.
Consider the following expressions P, Q and R. P: X = Y⋆Z Q: Y = X⋆Z R: X⋆Y⋆Z=1 Which of the following is TRUE? 
a.  Only P and Q are valid 
b.  Only Q and R are valid 
c.  Only P and R are valid 
d.  All P, Q, R are valid 
Answer:All P, Q, R are valid
