SISMEMBER tests if the given value is in the set. It returns 1 if the value is there and 0 if it is not.
SISMEMBER superpowers "flight" => 1 SISMEMBER superpowers "reflexes" => 0
SMEMBERS returns a list of all the members of this set.
SMEMBERS superpowers => 1) "flight", 2) "x-ray vision"
SUNION combines two or more sets and returns the list of all elements.
SADD birdpowers "pecking" SADD birdpowers "flight" SUNION superpowers birdpowers => 1) "pecking", 2) "x-ray vision", 3) "flight"