Problem 4 (total 13 points) Please fill in the blanks for the definitions specified below. (a) and are some of the (non) commercial Database Management Systems. - 3 points. (b) Relational Data Model is based on the theory in Math. -2 points. (c) Consider two relations called R1 and R2. The number of tuples in R1 and R2 are t and t2 respectively. The number of attributes of R1 and R2, on the other hand, are ni and n2. (t1, t2, ni, n2 >= 1). Fill in the blanks with formulae containing t, t2, ni, n2, functions, and constants. Each correct answer 2 points. If we apply RESTRICT operator to the relation R, the result will contain a minimum of and a maximum of tuples. The result relation will have a minimum of and a maximum of attributes. If we apply PROJECT operator to the relation R2, the result will contain a minimum of and a maximum of tuples. The result relation will have a minimum of and a maximum of attributes. Assuming that R1 and R2 are union-compatible, if we UNION R1 and R2 relations, the result will contain a minimum of and a maximum of tuples. The result relation will have a minimum of and a maximum of attributes. if we AJOIN R1 and R2 over an attribute ( or a set of attributes), the result will contain a minimum of and a maximum of tuples. The result relation will have a minimum of and a maximum of attributes