Q 4. Suppose the domain of the propositional function P(x, y) consists of pairs r and y, where r and y are positive integers less than 4. Write out the propositions below using disjunctions and conjunctions only. (a) 3.0P(1,3) (b) Vy-P(2,y) (c) Vx3yP(x,y) (d) 3.xVy-P(y,)