1. Augment the ER diagram of by introducing the entity PROFESSOR and suit-able r

1. Augment the ER diagram of by introducing the entity PROFESSOR and suit-able relations TEACHES (with entity CLASS) and ADVISES (with entity STUDENT). How can you specify a (funny) constraint like “a student cannot take a class that is taught by his or her advisor”? 2. Build the closures of the preceding formulas. 3. Is the closure of formula 6 true?

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