Could somebody please help me put this SQL query into a relational algebra. Thanks for your time and assistance.

SELECT EMP.NAME, EMPADDRESS, PROJ.PLOCATION, DEPT_LOCATIONS.DLOCATION
FROM EMPLOYEE, PROJECT, DEPT_LOCATIONS
WHERE PROJECT.PLOCATION = 'MD'
AND DEPT_LOCATIONS.DLOCATION <> &#39;MD&#39;

This is what I am trying to do:

Retrieving the names of people who worked on a projects that are in MD, but their locations are not in MD.