Make_access.1-T
type ('a, 'b) t
val many : ('at -> ('bt, 'a, 'b) Many.t) -> ('a, 'b) t -> ('at, 'bt) t
A legal implementation of this function must satisfy the following properties:
many Many.Accessed.return = Fn.id
Fn.compose (many f) (many g) = many (fun at -> Many.Accessed.bind (f at) ~f:g)