CMP.Preface:3.4 - Constituent actions in ongoing work

Updating a visited set can be part of executing a graph-search algorithm while a route-finding task is under way. Changing the required answer from any route to a route with the fewest edges changes which frontier-selection discipline suffices; a successful visited-set update alone does not establish the stronger result. The practitioner needs to connect the local update, the algorithm’s invariant and the route requirement, while retaining its representation and memory conditions. Knowing set operations and the desired route can leave that intermediate algorithmic reasoning missing.

FPF B.1.5.EW helps recover these constituent–whole connections; B.1.5.RS examines a proposed replacement. Use the parts of the vertical that can change the present result. A Method described here can require additional capability, available support and compatible resources at other grains.