Indeed, the type system when explained in detail is not that simple. Nevertheless, we believe that it can be used without detailed knowledge. In our experience

Indeed, the type system when explained in detail is not that simple. Nevertheless, we believe that it can be used without detailed knowledge. In our experience, programmers can pick up the system fast (e.g. after a 2 hour discussion). Similarly, programmers can easily write programs which type-check, even if they do not have a deep understanding of the type system (e.g. they need not memorise the table you mentioned). Type-checking is enough - given the guarantees by the type system, (data-race freedom and atomicity). The use of defaults reduces the annotation burden - typically to only 10%-20% of locations which allow them.