Without formula simplifications, jltl2ba will produce an APSet L0, L1, ...
With formula simplifications (upcoming commit), some APs can be missing
in the NBA (when irrelevant) or reordered (due to formula simplification).
We handle edge label construction as elsewhere in PRISM for DA, to take
this into account.
git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11186 bbc10eb1-c90d-0410-af57-cb519fbb1720