This module implements data types and functions for the evaluation of expressions with respect of given variable environments. The result, as well as the variable environments may map the variables to values according to their types. To this end, scalar and compound types are distinguished, where scalar values are elements of the types that can be atomically written by actions. As a consequence, variables having a scalar type can be mapped additionally to one of the values Vbot and Vtop (see below).

This module implements functions that are required by a simulator based on multi-valued evaluation. For more information, see function SimulationStep that is the essential function of this module.