news for release 936 since 935
------------------------------

* simple minimal unsatisfiable core (MUS) extractor 'picomus'
  (example for using 'picosat_mus_assumptions' and 'picosat_coreclause')

* added 'picosat_mus_assumptions'

* added 'picosat_{set_}propagations'

* new 'int' return value for 'picosat_enable_trace_generation' to
  check for trace code being compiled

news for release 935 since 926
------------------------------

* added 'picosat_failed_assumptions' (plural)

* new '-A <failedlits>' command line option

* fixed failed assumption issues

* added 'picosat_remove_learned'

* added 'picosat_reset_{phases,scores}'

* added 'picosat_set_less_important_lit'

* added 'picosat_res'

news for release 926 since 846
------------------------------

* random initial phase (API of 'picosat_set_default_phase' changed)

* fixed accumulative failed assumption (multiple times)

* fixed missing original clause in core generation with assumptions

* fixed debugging code for memory allocation

* shared library in addition to static library

* removed potential UNKNOWN result without decision limit

* added picosat_set_more_important_lit

* added picosat_coreclause

* propagation of binary clauses until completion

* fixed API usage 'assume;sat;sat'

* literals move to front (LMTF) during traversal of visited clauses

* switched from inner/outer to Luby style restart scheduling

* less agressive reduce schedule

* replaced watched literals with head and tail pointers

* add 'picosat_failed_assumption', which allows to avoid tracing and core
  generation, if one is only interested in assumptions in the core

* fixed a BUG in the generic iterator code of clauses
  (should rarely happen unless you use a very sophisticated malloc lib)

news for release 846 since 632
------------------------------

* cleaned up assumption handling (actually removed buggy optimization)

* incremental core generation 

* experimental 'all different constraint' handling as in our FMCAD'08 paper

* new API calls: 

  - picosat_add_ado_lit       (add all different object literal)
  - picosat_deref_top_level   (deref top level assignment)
  - picosat_changed           (check whether extension was possible)
  - picosat_measure_all_calls (per default do not measure adding time)
  - picosat_set_prefix        (set prefix for messages)

* 64 bit port (and compilation options)

* optional NVSIDS visualization code

* resource controlled failed literal implementation

* disconnect long clauses satisfied at lower decision level

* controlling restarts
