Consider the following data type and definitions.

data Tree a $=$ Leaf a $|$ Node a $($Tree a$)($Tree a$)$

tfold :: t $->($a $->$ t $->$ t $->$ t$)->$ Tree a $->$ t

tfold f g $($Leaf a$)=$ f

tfold f g $($Node x left right$)=$ g x $($tfold f g left$)($tfold f g right$)$

tree$1=$ Node $(2$::Int$)($Node $3($Leaf $2)($Leaf $4))($Node $2($Leaf $4)($Leaf $3))$