How can i convert the following SQL query to relational algebra?

This is the table:-

Lecturer(LecId, LecName)

Module(ModuleNumber, LecId, Schedule)

Enrol(StuId, ModuleNumber)

Student(StuId, firstName, lastName)
This is the SQL:-

SELECT LecName, Schedule FROM Lecturer, Module, Enrol, Student WHERE lastName = 'Burn' AND firstName = 'Edward' AND Module.ModuleNumber = Enrol.ModuleNumber AND Lecturer.LecId = Module.LecId AND Student.StuId = Enrol.StuId
How can i show this SELECT in relational algebra? With the sybols etc..