#time "on"

open System.Diagnostics

type State = { remaining: int64; aggregate: int64 }

let div = 10L

let rec skynet num size postback =
  if size = 1L then
    postback num
  else
    let agent = MailboxProcessor<_>.Start(fun inbox ->
      let rec loop state =
        async {
          let! value = inbox.Receive()
          if state.remaining = 1L then
            postback (state.aggregate + value)
          else
            return! loop { remaining = state.remaining - 1L; aggregate = state.aggregate + value }
        }
      loop { remaining = div; aggregate = 0L })
    for i = 0 to 9 do
      let subSize = size / div
      let subNum = num + (int64 i) * subSize
      skynet subNum subSize agent.Post

skynet 0L 1000000L (printfn "Value = %d")