Fortunately OCaml is (much more) than simply-typed lambda
calculus. Almost any feature of OCaml -- recursive data types,
recursive types, reference cells, mutable records, exceptions,
objects, recursive modules and polymorphic variants -- can be used to
express the fixpoint combinator. Sometimes there is more than one way
to use the same feature to express the fixpoint combinator. The more
and less known ways of expressing fix are collected in the following
document:

	http://okmij.org/ftp/ML/fixpoints.ml