global_cardinality(+Vs,
+Pairs, +Options)Global Cardinality constraint. Vs is a list of finite domain
variables, Pairs is a list of Key-Num pairs, where Key is an
integer and Num is a finite domain variable. The constraint holds iff
each V in Vs is equal to some key, and for each Key-Num pair
in Pairs, the number of occurrences of Key in Vs
is Num. Options is a list of options. Supported options are:
- consistency(value)
- A weaker form of consistency is used.
- cost(Cost, Matrix)
- Matrix is a list of rows, one for each variable, in the order
they occur in Vs. Each of these rows is a list of integers,
one for each key, in the order these keys occur in Pairs.
When variable v_i is assigned the value of key k_j, then the associated
cost is Matrix_{ij}. Cost is the sum of all costs.
