recursive types (and operations on them, like pretty-printing, comparison and unification) seem to be working.

big part of the code base still needs to be 'ported' to the updated type constructors.

structures/product.js

@@ -32,7 +32,7 @@ export const ModuleProduct = {l: [
         (a)
         (fnType
           (b)
-          (prodType(a)(b))
+          (prodType(() => a)(() => b))
         )
     ), GenericType),
 
@@ -40,7 +40,7 @@ export const ModuleProduct = {l: [
   ...typedFnType(getLeft, fnType =>
     makeGeneric((a, b) =>
       fnType
-        (prodType(a)(b))
+        (prodType(() => a)(() => b))
         (a)
     ), GenericType),
 
@@ -48,7 +48,7 @@ export const ModuleProduct = {l: [
   ...typedFnType(getRight, fnType =>
     makeGeneric((a, b) =>
       fnType
-        (prodType(a)(b))
+        (prodType(() => a)(() => b))
         (b)
     ), GenericType),
 ]};