The boss can be derived from the department the employee is assigned to and the head of this department. At first we'll give a short introduction into the syntax of the assertion language. The exact syntax is given in the appendix of the user manual. The object x is an instance of class c. The object x has an attribute to object y and this relationship is an instance of an attribute category with label l.
Structural integrity demands that the label l belongs to an attribute of a class of x.
The next literals are second class citizens in formulas. In contrast to the above literals they cannot be assigned to classes of the Telos object base. Consequently, they may only be used for testing, i.e. in a legal formula their parameters must be bound by one of the literals 1 - 3. The objects x and y are the same. The constants appearing in formulas must be names of existing objects in the object base or of type Integer, Real or String.