original.name="Reference_Valid_22"
======
>>> main.whiley
type Node is {
int item,
List next
} where !(next is null) ==> item < next->item
type List is null | &Node
public export method test():
List l1 = null
List l2 = new { item: 0, next: l1 }
// List l3 = new { item: 1, next: l2 }
---