ldsb_indomain_set(?X)

X

Set variable or set

Description

Simple predicate for instantiating a set LDSB variable to an element of its domain. If a set value is considered a binary number, where 1 is inclusion and 0 is exclusion, the value ordering is descending. For example:

go :-
    intset(S, 1, 3),
    Xs = [](S),
    ldsb_initialise(Xs, []),
    ( ldsb_indomain_set(S), writeln(S), fail
    ; true).
             

[1, 2, 3]
[1, 2]
[1, 3]
[1]
[2, 3]
[2]
[3]
[]
             

If X is already a ground set, then this predicate simply succeeds exactly once without leaving a choicepoint.

This predicate can be used with the search/6 predicate (see example).

Resatisfiable

Examples

go :-
        intsets(L, 3, 1, 10),
        ( foreach(S, L) do #(S, 3) ),
        ( fromto(L, [X|Xs], Xs, []) do
          ( foreach(Y, Xs), param(X) do
              #(X /\ Y, 0) ) ),
        Xs =.. [[]|L],
        ldsb_initialise(Xs, [values_interchange]),
        ( search(Xs, 0, input_order, ldsb_indomain_set, complete, []),
          writeln(Xs),
          fail
        ; true ).

See Also