(5 points each) Write the following queries in relational algebra, using the schema provided above. • If a query is long, feel free to break it up into a series of queries with intermediate answers stored in temporary relations (e. g. "let temp ="). • You can use abbreviations for Relational Algebra symbols such as S for SELECTION, P for PROJECTION, * for NATURAL JOIN, - for SET DIFFERENCE • Your queries must not be "state-dependent", that is, they should work without modification even if another instance of the database is given. (a) How many copies of the book titled "The Lost Tribe" are owned by the library branch whose name is "Sharpstown"? (b) How many copies of the book titled "The Lost Tribe" are owned by each library branch? (c) Retrieve the names of all borrowers who do not have any books checked out. (d) For each book that is loaned out from the Sharpstown branch and whose DueDate is prior to "September 1, 2018", retrieve the book title, the borrower’s name, and the borrower’s address. (e) For each book authored (or coauthored) by Stephen King, retrieve the title and the number of copies owned by the library branch whose name is "Central". (f) Retrieve all book titles

a  social news website  is an  internet  website  that features  user-posted stories. such stories are ranked based on popularity, as voted on by other users of the site or by website administrators. users typically comment online on the news posts and these comments may also be ranked in popularity. since their emergence with the birth of  web 2.0, social news sites have been used to link many types of information, including news, humor, support, and discussion. all such websites allow the users to submit content and each site differs in how the content is moderated. on the  slashdot  and  fark  websites,  administrators  decide which articles are selected for the front page. on  reddit  and  digg, the articles that get the most votes from the community of users will make it to the front page. many social news websites also feature an online comment system, where users discuss the issues raised in an article. some of these sites have also applied their voting system to the comments, so that the most popular comments are displayed first. some social news websites also have a  social networking  function, in that users can set up a user profile and follow other users' online activity on the website.