4.2.2.1. All-Different and related constraints

In this section: all_different, all_different_except, all_different_except_0, all_disjoint, all_equal, nvalue, symmetric_all_different.

all_different

 predicate all_different(array [$X] of var $$E: xs, set of $$E: except)

 predicate all_different(array [$X] of var set of $$E: xs)

 predicate all_different(array [$X] of var opt $$E: xs)

Constrain the elements in the array xs to be pairwise different, except for those that take a value in the set except (values in except may occur any number of times).
Constrain the elements in the array xs to be pairwise different.
Constrain the non-absent elements in the array xs to be pairwise different. The absent value <> is allowed to occur multiple times.

all_different_except

predicate all_different_except(array [$X] of var $$E: xs,
                               set of $$E: except)

Constrain the elements of the array xs to be pairwise different except for those values that appear in the set except.

This constraint is deprecated. Use all_different(xs, except) instead.

all_different_except_0

predicate all_different_except_0(array [$X] of var int: xs)

Constrain the elements of the array xs to be pairwise different except for those elements that are assigned the value 0.

This constraint is deprecated. Use all_different(xs, {0}) instead.

all_disjoint

predicate all_disjoint(array [$X] of var set of $$E: xs)

Constrain the array of sets of integers xs to be pairwise disjoint.

all_equal

predicate all_equal(array [$X] of var $$E: xs)
predicate all_equal(array [$X] of var set of $$E: xs)

Constrain the elements of the array xs to be all equal.

nvalue

 predicate nvalue(var int: n, array [$X] of var $$E: xs)

 predicate nvalue(var int: n, array [$X] of var opt $$E: xs)

 function var int: nvalue(array [$X] of var $$E: xs)

 function var int: nvalue(array [$X] of var opt $$E: xs)

1, 2.: Requires that the number of distinct values in xs is n.
3, 4.: Returns the number of distinct values in xs.

symmetric_all_different

predicate symmetric_all_different(array [int] of var int: xs)

Requires the array of integers xs to be all different, and for all i, xs[i]=j \(\rightarrow\) xs[j]=i.