================================================================================ P9211b J.A. Hillebrand "The ABP and the CABP - a comparison of performances in real time process algebra" (revised version of P9211) The main goal of this paper is to give a (small) case study in real time ACP. The Alternating Bit Protocol and the Concurrent Alternating Bit Protocol are specified and verified algebraically. Also a short introduction into real time ACP is given. We conclude that real time ACP is a fine formalism to work with, although we need a weaker notion of semantics for the verification of protocols than branching bisimulation, which we use throughout this paper. APPEARED AS: @inproceedings{Hil95, author = {J.A. Hillebrand}, booktitle = {{A}lgebra of {C}ommunicating {P}rocesses}, year = {1995}, editor = {A. Ponse and C. Verhoef and S.F.M. van Vlijmen}, publisher = {Springer-Verlag}, pages = {124--147}, series = {Workshops in Computing}, place = {Utrecht, The Netherlands}, title = {The {ABP} and the {CABP} -- a Comparison of Performances in Real Time Process Algebra} }