The relational division operation can be defined in multiple ways, depending on exactly how it should behave in different circumstances. For example, the relational division operation in the book will ignore the tuple (Guenter, tofu) when dividing monkey_likes by monkey_foods; thus, monkey_likes monkey_foods will be {(Jojo), (Guenter)}.

Using the definition of relational division given in the book, explain why the above is true. (Dont compute the entire result for every single step; just clearly show or explain why Guenter would appear in the result.)

Note that the expression RS,S(r) does not actually remove any attributes; it simply ensures that the order of the attributes is identical to that produced by the expression (RS(r) s).

r=s= Mr-s(r) - Mr-s((Ir-s(r) ~ s) - Mr-s,s(r)) r=s= Mr-s(r) - Mr-s((Ir-s(r) ~ s) - Mr-s,s(r))