In our first empirical study we investigated the performance of
two MAC algorithms that operate in the HVE, and compared them to
MGAC-2001, their counterpart in the non-binary representation. The
two MAC algorithms for the HVE are MHAC-2001, which stands for MAC
in the HVE that only instantiates original variables, and
MHAC-2001- which is a MAC algorithm that may instantiate any
variable (dual or original) according to the heuristic choice. As
stated by their names, all three algorithms use AC-2001 (GAC-2001)
to enforce AC. Although we also run experiments with the various
versions of FC, we do not include any results since these
algorithms are inefficient on hard problems (especially on hard
crossword puzzles). However, the qualitative comparison between
FC-based algorithms for the HVE and the non-binary representation
is similar to the comparison regarding MAC-based algorithms.