3.2.16 Partial Functions

We have considered implementing a model , given . We now consider implementing . The property is of interest; let   denote the domain of g, defined in terms of :

The function ,

when given an interval j and a set of extended real numbers, produces a valid description of the relationship between j and :

The relationship between j and is that of containment, formally defined as follows:

For the function , an evaluation of the model proceeds as follows:

The resulting domain description d', , is determined using d, , and :

The resulting value v', , depends on d'. If , the resulting value is given by the methods outlined earlier:

If , the resulting value is arbitrary:

as implies that for all .

Jeff Tupper

March 1996