9. Let x = A| B. T' = A'|B' be cuts in Q. We defined THI = (A+ A') | rest of Q. (a) Show that although B + B' is disjoint from A + A', it may happen in degenerate cases that Q is not the union of A + A' and B + B'. (b) Infer that the definition of a +r' as (A+ A) | (B +B') would be incorrect. (c) Why did we not define r . I' = (A . A') | rest of