+$ model [count=@ud]
+$ message
  %noop
  [%set value=@ud]
++ main (program init update view subs)
++ init |= input=@t ^- model [count=0]
++ update |= [event=message current=model]
  ?- event
    %noop [current ~]
    [%set value]
      ?- (gth value 10)
        %.y [current(count=value) ~]
        %.n [current ~]
++ view |= state=model ^- (element message) (text "view")
++ subs |= state=model ^- (list (sub message)) ~