Exercises part 2

1. Implement interfaces Equals, Comp, Concat, and Empty for pairs, constraining your implementations as necessary. (Note, that multiple constraints can be given sequentially like other function arguments: Comp a => Comp b => Comp (a,b).)

2. Below is an implementation of a binary tree. Implement interfaces Equals and Concat for this type.

   data Tree : Type -> Type where
     Leaf : a -> Tree a
     Node : Tree a -> Tree a -> Tree a