1. Consider the following GRADEBOOK relational schema describing the data for a grade book of a particular instructor. The attributes A, B, C, and D of COURSES store grade cutoffs (30 points) CATALOG(C#, Ctitle) STUDENT(Sid, Fname, Lname, Minit) COURSES(Term, SecNo, C?A, B, C, D) ENROLLS(Sid, Term, SecNo) Specify the following queries using the Relation Algebra interpreter on the GRADEBOOK database schema: Retrieve the names of students enrolled in the Automata class during the Spring 2018 term Retrieve the Sid values of students who are enrolled in both COP 4710 and COP 2551. Retrieve the Sid values of students who are enrolled in COP 4710 or COP 2551 Retrieve the names of students who are not enrolled in any class. Retrieve the names of students who are enrolled in all courses in the CATALOG table