CREATE TABLE player (Residence VARCHAR, gender VARCHAR)

Show the residences that have both a player of gender 'M' and a player of gender 'F'.
SELECT Residence FROM player WHERE gender = "M" INTERSECT SELECT Residence FROM player WHERE gender = "F"
SELECT "Residence" FROM "player" WHERE "M" = "gender" INTERSECT SELECT "Residence" FROM "player" WHERE "F" = "gender"