+$ message
  %start
  %stop
+$ model [count=@ud]
++ main (program (init) update view subs)
++ init |= input=@t ^- model [count=0]
++ update |= [msg=message state=model]
  ^- [model (list (cmd message))] [state ~]
++ view |= state=model ^- (element message) (text "view")
++ subs |= state=model
  ^- (list (sub message))
    (~)