module Tuple: Tuplemodule T2:sig..end
module T3:sig..end
module Make:
module type Comparable_sexpable =sig..end
module Comparable:
module type Hashable_sexpable =sig..end
module Hashable:
Hashable and Hashable_t functors is that the former's
result type doesn't contain type t and the latter does.
module Hashable_t:
module Sexpable: