So I was asked to make a Binary Tree in Haskell taking as input a list of Integers. Below is my code. My problem is that the last element of the list is not getting inserted in the Tree. For example [1,2,3,4] it only inserts to the tree until "3" and 4 is not inserted in the Tree.

    data ArbolBinario a = Node a (ArbolBinario a) (ArbolBinario a) | EmptyNode
deriving(Show)

    insert(x) EmptyNode= insert(tail x) (Node (head x) EmptyNode EmptyNode)

    insert(x) (Node e izq der)
     |x == [] = EmptyNode --I added this line to fix the Prelude.Head Empty List error, after I added this line the last element started to be ignored and not inserted in the tree
     |head x == e = (Node e izq der)
     |head x < e = (Node e (insert x izq) der)
     |head x > e = (Node e izq (insert x der))

Any ideas on whats going on here? Help is much appreciated