The  SUBCELAR6 directory contains 4  instances that have been extracted from
the challenging scen06 problem from the  CELAR data-set. These instances are
ideal  for benchmarking  Max-CSP  algorithms (algorithms trying  to  solve a
problem of constraint violation minimisation optimally). All together, these
instances induce a compulsory violation cost of 3389, which is exactly equal
to the cost of the best  solution found.  This  is how scen06 optimality was
proved.  The first resolution  of  these problems needed  around 32  days of
cpu-time  (using a Lisp implementation  of the Russian Doll Search algorithm
on Sparc 5).