prelude's elem on Foldable suffices so remove SnocVect-specific imple…

…mentation

src/Data/SnocVect.idr

@@ -2,8 +2,6 @@ module Data.SnocVect
 
 import Data.Vect
 
-%hide Prelude.Types.elem
-
 %default total
 
 ||| A Backwards Vect
@@ -184,12 +182,6 @@ Traversable (SnocVect k) where
   traverse _ Lin = pure Lin
   traverse f (xs :< x) = [| traverse f xs :< f x |]
 
-||| Check if something is a member of a snoc-vect using the default Boolean equality.
-public export
-elem : Eq a => a -> SnocVect k a -> Bool
-elem x Lin = False
-elem x (sx :< y) = x == y || elem x sx
-
 ||| Find the first element of the snoc-vect that satisfies the predicate.
 public export
 find : (a -> Bool) -> SnocVect k a -> Maybe a