For all the below queries (1-8) write the algebra expressions:

1-Consider the below database schema:

Professor(ssn, profname, status)

Course(crscode, crsname, credits)

Taught(crscode, semester, ssn)

Query1) Return the ssn of professors who have taught COMP440.

Query2) Return the ssn of professors who have taught COMP440 in Spring 2020 semester.

Query3) Return the ssn of professors who have taught both COMP440 and COMP541.

Query4) Return the codes of courses that have never been taught.

Query5) Return the names of courses that have never been taught.

Query6) Return the names of professors who ever taught COMP440.

Query7) Return the names of full professors who ever taught COMP440.

2- Consider the below database schema: Student(id, name, address, status) Transcript(studid, crscode, semester, grade)

Query8) Return the names of students and the codes of courses which they got grade A.