  In this work, we examine two approaches to interprocedural data-flow analysis
of Sharir and Pnueli in terms of precision: the functional and the call-string
approach. In doing so, not only the theoretical best, but all solutions are
regarded which occur when using abstract interpretation or widening
additionally. It turns out that the solutions of both approaches coincide. This
property is preserved when using abstract interpretation; in the case of
widening, a comparison of the results is not always possible.
