1) For each of the following pairs of expressions find a most general unifier, or explain why a unifier cannot be found. . f(x, b, g(b) ) and f(a, Z, Y) . f (x, b, g(b)) and f(a, b, Y) . f(a, X, g(y, Y) ) and f(Y, b, Z) .E(x, Y, g(Z)) and (X, g(h (Z)), Y) [F, [A, 1, B], [A, B], 2] and [C, [D, D, E], C, E] 2) Use the semantic approach to check the following possible entailments Show your work. 1) For each of the following pairs of expressions find a most general unifier, or explain why a unifier cannot be found. . f(x, b, g(b) ) and f(a, Z, Y) . f (x, b, g(b)) and f(a, b, Y) . f(a, X, g(y, Y) ) and f(Y, b, Z) .E(x, Y, g(Z)) and (X, g(h (Z)), Y) [F, [A, 1, B], [A, B], 2] and [C, [D, D, E], C, E] 2) Use the semantic approach to check the following possible entailments Show your work