nominal browser = ()
nominal click = ()
nominal submit = ()

union event_capability target event =
    | BrowserClick :: event_capability browser click
    | BrowserSubmit :: event_capability browser submit

union event_handler target event =
    | EventHandler :: forall target event. event_capability target event * string -> event_handler target event

inl install_click (handler : event_handler browser click) : string =
    match handler with
    | EventHandler _ => "increment:browser-click"

inl main () : string =
    install_click (EventHandler (BrowserClick, "increment"))