person (ID, name) parent (ID, parentID) manages (ID, mgrID) In the parent relation, ID is the ID of the child and in manages ID is the ID of the employee.

you may assume that every ID in the database in included in ID (person), and that there are no null values in the database.

But note that there may be people who are not listed as being a child, or not listed as being a parent, or not listed as being an employee, or not listed as being a manager.

Write a relational algebra(RA) for

"Find the ID and name of each person who manages all children of the person with ID 12345."