Here, we describe the set of FDBG services and commands necessary to do
a simple debugging session. No major modification of your CLP(FD)
program is necessary to use FDBG this way. Debugging more
complicated programs, on the other hand, might also require user
written extensions to FDBG, since the wallpaper trace produced by the
built-in visualizer fdbg_show could be too detailed and therefore
hard to analyze. See FDBG Advanced Usage.