10.39.1 Notes

Domain variables

Only variables with finite integer domains are supported. This includes boolean variables which are considered finite integer domain variables with the domain 0..1. Domain variables declared to be of type var int are initially given the finite integer domain inf..sup, and constrained to -1073741823..1073741823 before any search is performed on them.

Optimization problems

Only variables with finite integer domains can be optimized in minimize and maximize solve items. The int_float_lin/4 expression as described in the FlatZinc specification is thus not supported.

Solve annotations

• The solve annotations currently supported are bool_search/4, int_search/4, labelling_ff/0, and seq_search/1.
• The FlatZinc specification describes several exploration strategies. Currently, the only supported exploration strategies are complete and fail.
• When no solve annotation is given, a most constrained heuristic is used on all problem variables (excluding those that have a var_is_introduced annotation; see below). This corresponds to labeling/2 of library(clpfd) with the option ffc.
• The choice method indomain_random as described in the FlatZinc specification uses random_member/2 of library(random). The random generator of SICStus is initialized using the same seed on each start up, meaning that the same sequence will be tried for indomain_random on each start up. This behavior can be changed by setting a different random seed using setrand/1 of library(random).

Constraint annotations

Constraint annotations are currently ignored.

Variable annotations

Variable annotations are currently ignored, except var_is_introduced, which means that the corresponding variable is not considered in any default labeling (such as when no search annotation is given or when the labelling_ff search annotation is given).