Sorting Implicit Outputs in Digital Simulation

The Stein-Rose sorting algorithm for digital simulation is reexamined and reformulated in current terms. It is pointed out that the algorithm already contains within itself the means for the automatic detection of feedback loops (implicit outputs) in analog programs. The algorithm is then extended so that it can handle implicit outputs and the extended version is shown to be finite. Thus compilers for digital simulation languages utilizing the extended algorithm need not require that programmers take a priori action either to remove feedback loops from analog programs or to identify such loops to the compiler.