(en) Nadji Gauthier et François Pottier, « Numbering Matters: First-Order Canonical Forms for Second-Order Recursive Types », Proceedings of the ACM SIGPLAN International Conference on Functional Programming (ICFP), vol. 39, no 9, , p. 150-161 (DOI10.1145/1016850.1016872, lire en ligne [PDF])
(en) « The OCaml system, § 6.4. Type expressions : Aliased and recursive types », sur caml.inria.fr (consulté le ) : « Recursive types for which there exists a recursive path that does not contain an object or polymorphic variant type constructor are rejected, except when the -rectypes mode is selected. »
gallium.inria.fr
(en) Nadji Gauthier et François Pottier, « Numbering Matters: First-Order Canonical Forms for Second-Order Recursive Types », Proceedings of the ACM SIGPLAN International Conference on Functional Programming (ICFP), vol. 39, no 9, , p. 150-161 (DOI10.1145/1016850.1016872, lire en ligne [PDF])