Changelog PHAVer 
v.0.38
12.01.09
- fixed bug in parser that caused a parse error on constraints of the form ( a | b ) & c
07.01.09
- added new option in f/b-refinement: 1xx as REACH_FB_REFINE_METHOD now suppresses tightening of the constraints until convergence
- fixed bug in trans_and_time_post_assign that caused a crash if non-convex hull and limiting bits were used. 
v.0.37
06.12.15 
- fixed splitting with unbounded invariants
- fixed bug in parser that wouldn't allow parantheses around constraints (introducing another shift/reduce conflict)
- added -y as a switch to get parser debugging output
- added "reg.merge_splitted;" to join locations that were splitted (remove the @ from the names, simplify)

v.0.36
06.09.21 revised pairwise discrete composition
- added syntax: several labels can be specified using label{ext1,ext2,...}
- added remove_redundant after intersection of cvs
- added memory-saving functions: MEMORY_LEVEL=4 is highest at the moment, replacing cvs with their minimal constraint systems after composition, and when adding them to the passed&waiting list

v.0.35
06.06.21 added LIMIT_CONSTRAINTS_METHOD to parser
       - moved time elapse to after limiting in when not using convex-hull (convex hull already has this order)
       - renamed in parser "REFINE" to "PARTITON" where applicable
v.0.34
06.06.20 Implemented incremental partitioning for unbounded invariant (experimental)
06.06.20 Re-implemented is_reachable(forbidden_states)
06.06.15 Fixed bug due to which the derivative of parameters was not constant
v.0.33
06.05.24 Fixed bug in parser that only allowed to specify sets of states of the last automaton defined. (Thanks to Gabriela Marin for finding the bug.)
06.05.24 Additional functionality to loc_union and loc_intersection. They can now be used to define new sets of states.

v.0.30
06.02.23 Fixed bug through which the use of undefined variables in automaton definitions was possible if they were primed.
06.02.21 Major syntax changes:
- In the flow definition (wait {...}), derivatives are now designated by primes ('), and variables occur in their unprimed form. This is the exact opposite of previous versions.
- save_gen_fp(fname) -> print("fname",2);
- save_con_fp(fname) -> print("fname",1);
- Filenames must now be enclosed in double quotes, allowing extra characters for path etc.

v.0.27
06.01.23 Fixed major bug in Constraint_restrict_to_dim, which caused static constraints to always appear as equalities.
