As a first application of the use of chains, we note that boundary value problems can be specified, and the result of their solution return via finite chains. As an example, we may specify the boundary conditions for the Laplace equation by defining a 1-chain on a 1-complex representing the boundary of a 2 dimensional region. The result can be returned as a 0-chain. This shows how the computer implementation of chains provides a uniform means of incorporating ``legacy codes'' into the SimLab environment.