Delayed_result.Syntax
val let** : ('a, 'b) t -> ('a -> ('c, 'b) t) -> ('c, 'b) t
val let++ : ('a, 'b) t -> ('a -> 'c) -> ('c, 'b) t
val let+* : ('a, 'b) t -> ('a -> ('c, 'b) Result.t) -> ('c, 'b) t