(A) Consider the following schema: Suppliers(sid: integer, sname: varchar(20), address: varchar(50)) Parts(pid: integer, pname: varchar(20), color: varchar(15)) Catalog(sid: integer, pid: integer, cost: real) The key fields are underlined Domains of each field are listed after field name The Catalog relation lists prices charged for parts by Suppliers Write the following queries in relational algebra (30 points): (i) Find the names of suppliers who supply some blue part () Find the sids of suppliers who do not supply a red part (i) Find the sids of suppliers who supply some blue or red part (iv) Find the sids of suppliers who supply some blue part and some red part (v) Find the sids of suppliers who supply every blue part (vi) Find the pids of parts supplied by every supplier at less than $50. (If a supplier either does not supply the part or charges more than $50, the part is not selected.)