In listConservedSets, computing descendants for P and ancestors for Q, and not the other way round.
Add showSetSymbols.
Factor out showGraph and redefine showSymbolGraph.
Add showSymbolsGraph.
Remove a redundant important in Formatter.
Add the possibility to show the behaviour graph.
Factor out doRSAction.
Make showing of . for the empty set optional.
Add a brief documentation for showing the behaviour graph.