Then this example shows how R-SPL represents activity parameters. Every action can have a time which may be a quite complex data element (e.g. for repeating activities), but in this case it is only specified as the duration of this stirring action, so the interval that would in a real performed activity have a start and end point in time, here it has only a width of 4 hours. Then there can be any number of other parameters, of which all settings, presets, we define as "control variables"