TY - GEN
T1 - Breaking row and column symmetries in matrix models
AU - Flener, P.
AU - Frisch, A.M.
AU - Hnich, B.
AU - Kiziltan, Z.
AU - Miguel, I.
AU - Pearson, J.
AU - Walsh, T.
PY - 2002/9
Y1 - 2002/9
N2 - We identify an important class of symmetries in constraint
programming, arising from matrices of decision variables where rows and columns can be swapped. Whilst lexicographically ordering the rows (columns) breaks all the row (column) symmetries, lexicographically ordering
both the rows and the columns fails to break all the compositions of the row and column symmetries. Nevertheless, our experimental results show that this is effective at dealing with these compositions of
symmetries. We extend these results to cope with symmetries in any number of dimensions, with partial symmetries, and with symmetric values. Finally, we identify special cases where all compositions of the row and column symmetries can be eliminated by the addition of only a linear number of symmetry-breaking constraints.
AB - We identify an important class of symmetries in constraint
programming, arising from matrices of decision variables where rows and columns can be swapped. Whilst lexicographically ordering the rows (columns) breaks all the row (column) symmetries, lexicographically ordering
both the rows and the columns fails to break all the compositions of the row and column symmetries. Nevertheless, our experimental results show that this is effective at dealing with these compositions of
symmetries. We extend these results to cope with symmetries in any number of dimensions, with partial symmetries, and with symmetric values. Finally, we identify special cases where all compositions of the row and column symmetries can be eliminated by the addition of only a linear number of symmetry-breaking constraints.
U2 - 10.1007/3-540-46135-3_31
DO - 10.1007/3-540-46135-3_31
M3 - Conference contribution
SN - 978-3-540-44120-5
T3 - Lecture Notes in Computer Science
SP - 462
EP - 477
BT - Proceedings of the 8th International Conference on Principles and Practice of Constraint Programmin
PB - Springer
CY - Berlin / Heidelberg
T2 - Principles and Practice of Constraint Programming - (CP 2002)
Y2 - 23 July 2001 through 26 July 2001
ER -