
alldifferent_matrix(+Matrix)

   Constrain the rows and columns of Matrix to be different values

Arguments
   Matrix              A two dimensional square matrix of Variables or integer

Type
   library(ic_global)

Description

    This constraint is a matrix version of alldifferent. Matrix is a two
    dimensional square (NxN) matrix, and the constraint ensures that the 
    elements in each row and column of the matrix are different. The same
    value can occur in different rows and columns. It is logically 
    equivalent to imposing 2N alldifferent constraints, on each row and column,
    but it allows more reasoning because it considers the rows and columns 
    together. The alldifferent constraint used is the lib(ic_global) version.
    The maximum propagation occurs when the variables' domains also
    have N values

    This is currently a prototype -- the constraint has not been tested
    very extensively and little effort has been spent to optimise performance.
    We welcome any feedback on using this constraint.

    This constraint is described in J.-C. Regin and C. Gomes,
    'The Cardinality Matrix Constraint', CP 2004.


See Also
   alldifferent / 1, fd_global : alldifferent_matrix / 1, fd_global_gac : alldifferent_matrix / 1, ic_global_gac : alldifferent_matrix / 1
