:: a -> [a] -> Bool -package:brittany -package:stack package:base-unicode-symbols

(∈) = elem U+2208, ELEMENT OF
(∉) = notElem U+2209, NOT AN ELEMENT OF
(∈) = elem U+2208, ELEMENT OF
(∉) = notElem U+2209, NOT AN ELEMENT OF
(∋) = flip (∈) U+220B, CONTAINS AS MEMBER
(∌) = flip (∉) U+220C, DOES NOT CONTAIN AS MEMBER
(∋) = flip (∈) U+220B, CONTAINS AS MEMBER
(∌) = flip (∉) U+220C, DOES NOT CONTAIN AS MEMBER