- ord_setproduct(+Set1, +Set2, ?SetProduct)
- is true when SetProduct is the cartesian product of Set1 and Set2.
The product is represented as pairs Elem1-Elem2, where Elem1 is an
element from Set1 and Elem2 is an element from Set2.
The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.
- list_to_ord_set(+List, -OrdSet) is det
- Transform a list into an ordered set. This is the same as
sorting the list.
- ord_intersect(+Set1, +Set2) is semidet
- True if both ordered sets have a non-empty intersection.
- is_ordset(@Term) is semidet
- True if Term is an ordered set. All predicates in this library
expect ordered sets as input arguments. Failing to fullfil this
assumption results in undefined behaviour. Typically, ordered
sets are created by predicates from this library, sort/2 or
- ord_add_element(+Set1, +Element, ?Set2) is det
- Insert an element into the set. This is the same as
ord_union(Set1, [Element], Set2).
- ord_del_element(+Set, +Element, -NewSet) is det
- Delete an element from an ordered set. This is the same as
ord_subtract(Set, [Element], NewSet).
- ord_union(+Set1, +Set2, -Union, -New) is det
- True iff
ord_union(Set1, Set2, Union) and
ord_subtract(Set2, Set1, New).
- ord_seteq(+Set1, +Set2) is semidet
- True if Set1 and Set2 have the same elements. As both are
canonical sorted lists, this is the same as ==/2.
- - sicstus
- ord_intersection(+PowerSet, -Intersection) is semidet
- Intersection of a powerset. True when Intersection is an ordered set
holding all elements common to all sets in PowerSet. Fails if
PowerSet is an empty list.
- - sicstus
- ord_memberchk(+Element, +OrdSet) is semidet
- True if Element is a member of OrdSet, compared using ==. Note
that enumerating elements of an ordered set can be done using
Some Prolog implementations also provide ord_member/2, with the
same semantics as ord_memberchk/2. We believe that having a
semidet ord_member/2 is unacceptably inconsistent with the *_chk
convention. Portable code should use ord_memberchk/2 or
- - Richard O'Keefe
- ord_symdiff(+Set1, +Set2, ?Difference) is det
- Is true when Difference is the symmetric difference of Set1 and
Set2. I.e., Difference contains all elements that are not in the
intersection of Set1 and Set2. The semantics is the same as the
sequence below (but the actual implementation requires only a
ord_union(Set1, Set2, Union),
ord_intersection(Set1, Set2, Intersection),
ord_subtract(Union, Intersection, Difference).
?- ord_symdiff([1,2], [2,3], X).
X = [1,3].
- ord_subset(+Sub, +Super) is semidet
- Is true if all elements of Sub are in Super
- ord_union(+Set1, +Set2, -Union) is det
- Union is the union of Set1 and Set2
- ord_empty(?List) is semidet
- True when List is the empty ordered set. Simply unifies list
with the empty list. Not part of Quintus.
- ord_subtract(+InOSet, +NotInOSet, -Diff) is det
- Diff is the set holding all elements of InOSet that are not in
- ord_union(+SetOfSets, -Union) is det
- True if Union is the union of all elements in the superset
SetOfSets. Each member of SetOfSets must be an ordered set, the
sets need not be ordered in any way.
- - Copied from YAP, probably originally by Richard O'Keefe.
- ord_disjoint(+Set1, +Set2) is semidet
- True if Set1 and Set2 have no common elements. This is the
negation of ord_intersect/2.
- ord_intersection(+Set1, +Set2, ?Intersection, ?Difference) is det
- Intersection and difference between two ordered sets.
Intersection is the intersection between Set1 and Set2, while
Difference is defined by
ord_subtract(Set2, Set1, Difference).
- See also
- - ord_intersection/3 and ord_subtract/3.
- ord_intersection(+Set1, +Set2, -Intersection) is det
- Intersection holds the common elements of Set1 and Set2. Uses
ord_disjoint/2 if Intersection is bound to
 on entry.
- ord_intersect(+Set1, +Set2, -Intersection)
- Intersection holds the common elements of Set1 and Set2.
- - Use ord_intersection/3
- ord_selectchk(+Item, ?Set1, ?Set2) is semidet
- Selectchk/3, specialised for ordered sets. Is true when
select(Item, Set1, Set2) and Set1, Set2 are both sorted lists
without duplicates. This implementation is only expected to work
for Item ground and either Set1 or Set2 ground. The "chk" suffix
is meant to remind you of memberchk/2, which also expects its
first argument to be ground.
ord_selectchk(X, S, T) =>
ord_memberchk(X, S) & \+
- - Richard O'Keefe