var b : Type

var a :Type+

type List a : Type

free type List a ::= Nil | Cons(head : a; tail : List a)

free type List a ::= Nil | Cons(head : a; tail : List b)

free type List a ::= Nil | Cons(head : a; tail : List a b)

free type List a ::= Nil | Cons(head : a; tail : List (List a))

free type Tree a ::= Leaf | Branch(head : Tree a; tail : Tree a)

generated type Tree1 a ::= Leaf | Branch(head : Tree a; tail : Tree1 a)

type Tree2 a ::= Leaf | Branch(head : Tree a; tail : Tree2 a)

free type even a ::= rek(odd a) ; odd a ::= rek(even a)

free type even2 a ::= rek(odd2 (odd2 a)) ; odd2 a ::= rek(even2 a)