================================================================================ P9612 J.A. Hillebrand "Transforming an ASF+SDF specification into a ToolBus application" An algebraic specification of the natural numbers is being translated into C code, such that the modular structure of the specification is preserved. We use the ToolBus, a component interconnection architecture, to couple the resulting C programs. The result is a calculation tool, consisting of independent components, which can work with infinitely large (positive) integers without running into some maximum integer value. It supports different forms of representation of numbers in a flexible way.