module type Basic2 =sig
..end
('a,'b result)
).type ('a, 'e)
t
val bind : ('a, 'e) t ->
('a -> ('b, 'e) t) -> ('b, 'e) t
val map : [ `Custom of
('a, 'e) t ->
f:('a -> 'b) -> ('b, 'e) t
| `Define_using_bind ]
val return : 'a -> ('a, 'b) t