Slide 47 of 65
This is the revised package for the level type with the inclusion of the necessary types, subtypes and the actual resolution function. This example simply illustrates how a bus resolution function is defined.
Note that the resolution function takes in a level_vector, which is really an unconstrained array, and returns a single level value as is required by the language. The subtype level_resolved_x is the signal subtype that is associated with the bus resolution function and level_resolved_x_vector is an array of signals of that subtype.