[PPL-devel] About the last (huge) commit on BD_Shape.

[Enea Zaffanella]

I finally managed to commit my (huge) changes to the implementation of 
BDSs. The main novelty are:

- shortest-path reduction no longer compromises shortest-path closure 
(note: I still have to implement the extraction of constraints for the 
case of a dbm in reduced form);

- affine images, preimages and generalized affine images have been 
rewritten almost from scratch; they should be less buggy than before 
(this is definitely the case for the case of generalized images); at the 
very least, the current code is no longer relying upon unreasonable 
assumptions on the kind of coefficients and the sign of denominators.

Some tests will now fail: I strongly suspect that for some of them there 
is no real bug, but rather the "known_result" was wrong.

In summary, there still is plenty of things to do.

Ciao,
Enea.