
  int => Js.Promise.t(Belt.Result.t(int, exn)),
  Js.Promise.t(Belt.Result.t(int, exn))
) => Js.Promise.t(Belt.Result.t(int, exn))">Result.Promise.andThen</span>
         (fun <span class='pattern-ident' data-type="int">x</span>  -&gt; ((<span class='ident' data-type="int">x</span> <span class='operator' data-type="(int, int) => int">+</span> <span class='int' data-type="int">2</span>) <span class='operator' data-type="(int, int => Belt.Result.t(int, exn)) => Belt.Result.t(
  int,
  exn
)">|&gt;</span> <sp