Comparing and Sorting

Predicates

?Term1 = ?Term2

Succeeds if Term1 and Term2 unify.

?Term1 == ?Term2

Succeeds if Term1 and Term2 are identical terms.

?Term1 @< ?Term2

Succeeds if term Term1 is before term Term2 in the standard ordering.

?Term1 @=< ?Term2

Succeeds if term Term1 is before or equal to Term2 in the standard ordering.

?Term1 @> ?Term2

Succeeds if term Term1 is after term Term2 in the standard ordering.

?Term1 @>= ?Term2

Succeeds if term Term1 is after or equal to Term2 in the standard ordering.

?Term1 \= ?Term2

Succeeds if Term1 and Term2 are not unifiable.

?Term1 \== ?Term2

Succeeds if Term1 and Term2 are not identical terms.

array_sort(+Key, +Order, +Random, -Sorted)

Succeeds if Sorted is the sorted version of Random. The sort is done according to the Key and Order specifications.

compare(-Ordering, ?Term1, ?Term2)

Succeeds if Ordering is a special atom which describes the ordering between Term1 and Term2.

compare_instances(-Relationship, ?Term1, ?Term2)

Succeeds if Relationship is an atom describing the instance relationship between Term1 and Term2.

current_domain(?Name, -DefModule, -DomainDef)

Name is the name of a visible domain, defined by DomainDef in DefModule

local domain(++Def), export domain(++Def)

Define a domain (a set of symbols mapped to natural numbers)

domain_index(+Value, -Domain, -Index)

Value is defined in Domain with positional number Index

instance(?Instance, ?Term)

Succeeds if Instance is an instance of Term.

keysort(+List1, -List2)

Succeeds if List2 is a sorted list version of List1, whose elements are of the form Key-Value. The sort is done according to the value of the key Key.

merge(+List1, +List2, -List3)

Succeeds if List3 is a merged list of List1 and List2. If both lists are sorted, List3 will be sorted.

merge(+Key, +Order, +List1, +List2, -List3)

Succeeds if List3 is a merged list of List1 and List2. If both lists are sorted, List3 will be sorted. The sort is done according to the Key and Order specifications.

msort(+List1, -List2)

Succeeds if List2 has the same elements as List1 and is sorted.

not_unify(?Term1, ?Term2)

Succeeds if Term1 and Term2 are not unifiable.

number_merge(+List1, +List2, -List3)

Succeeds if List3 is a merged list of List1 and List2. If both lists are sorted, List3 will be sorted.

number_sort(+List1, -List2)

Succeeds if List2 is the numerically ordered version of List1.

occurs(?Simple, ?Term)

Succeeds if Simple is a variable or an atomic type that occurs in the term Term.

prune_instances(+List, -PrunedList)

Succeeds if PrunedList is the smallest list that subsumes the list List.

sort(+List1, -List2)

Succeeds if List2 is the strictly ordered, no duplicates version of List1.

sort(+Key, +Order, +Random, -Sorted)

Succeeds if Sorted is the sorted list version of Random. The sort is done according to the Key and Order specifications.

term_hash(?Term, +Depth, +Range, -Hash)

Computes a hash value for an arbitrary term

variant(?Term1, ?Term2)

Succeeds if Term1 is a variant of Term2.

?Term1 ~= ?Term2

The sound difference operator. Succeeds if the two terms cannot be unified, fails if they are identical, otherwise it delays.