`val return : 'a ‑> ('a, 'b) Core_kernel.Result.t Deferred.t`
`val bind : ('a, 'e) Core_kernel.Result.t Deferred.t ‑> f:('a ‑> ('b, 'e) Core_kernel.Result.t Deferred.t) ‑> ('b, 'e) Core_kernel.Result.t Deferred.t`
`val map : ('a, 'e) Core_kernel.Result.t Deferred.t ‑> f:('a ‑> 'b) ‑> ('b, 'e) Core_kernel.Result.t Deferred.t`
`val both : ('a, 'e) Core_kernel.Result.t Deferred.t ‑> ('b, 'e) Core_kernel.Result.t Deferred.t ‑> ('a * 'b, 'e) Core_kernel.Result.t Deferred.t`
`module Open_on_rhs : sig ... end`