Hello everyone. I'm trying to write a code which works on binary trees. When I write code like this with a tree with empty nodes :

data Tree = Empty | Node Integer Tree Tree

function Node a (Node b Empty Empty) (Node c Empty Empty)

it works fine.

But when I try to create a more generic code like this which could work with trees who don't have empty nodes in grandchild level :

function Node a (Node b Tree Tree) (Node c Tree Tree )

I get this error : Undefined data constructor "Tree"

Can you help me with creating more generic code please?

Thanks