SQL query to a relational algebra

Question

How I can translate the SQL query to a relational algebra expression?

SELECT P.Name

FROM Players P, Games G

WHERE P.Id =  G.PlayerId

    AND P.Game = 'Football' AND G.Season ='2019'

where:

Players (Id, Name, Game)

Games (PlayerId, GameCode, Season)

Answer 1

The query

SELECT P.Name FROM Players P, Games G WHERE P.Id = G.PlayerId AND P.Game = 'Football' AND G.Season ='2019'

will have an equivalent relational algebra form as follows:

π_Name σ_{Id = PlayerId ∧ Game = 'Football' ∧ Season ='2019'} (Players ×Games)