F#: Reduce function dependencies

reduce-deps.fs

type Entity = { ArrivalDate: DateTime }

type IDb =
    abstract member Conn: string

type Workflow<'Result> = Workflow of (IDb -> 'Result)

let db = { new IDb with member x.Conn = "asd"  }

let run idb (Workflow fn) = fn idb

let bind f fn =
    Workflow(fun d ->
        let r = run d fn
        run d (f r))

type WorkflowBuilder() =
    member _.Bind(x, f) = bind f x
    member _.Return (x) = Workflow(fun _ -> x)
    member _.ReturnFrom (workflow: Workflow<'Result>) = workflow

let workflow = new WorkflowBuilder()

let createEntity arrivalDate  =
    let create db =
        { ArrivalDate = arrivalDate }
    Workflow create

let result = workflow {
    let! p = createEntity (System.DateTime.Now)
    return p
}