library

Prolog files

aggregate.pl  -- Aggregation operators on backtrackable predicates
ansi_term.pl
ansi_format/3	Format text with ANSI attributes.
ansi_get_color/2	Obtain the RGB color for an ANSI color parameter.
ansi_hyperlink/2	Create a hyperlink for a terminal emulator.
ansi_hyperlink/3	Create a hyperlink for a terminal emulator.
tty_url_hook/2	Hook for location_url/2.
console_color/2	Hook that allows for mapping abstract terms to concrete ANSI attributes.
message_line_element/2	Hook implementation that deals with ansi(+Attr, +Fmt, +Args) in message specifications.
apply.pl
convlist/3	Similar to maplist/3, but elements for which call(Goal, ElemIn, _) fails are omitted from ListOut.
exclude/3	Filter elements for which Goal fails.
foldl/4	Fold an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("fold-left"), using columns of m list elements as arguments for Goal.
foldl/5	Fold an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("fold-left"), using columns of m list elements as arguments for Goal.
foldl/6	Fold an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("fold-left"), using columns of m list elements as arguments for Goal.
foldl/7	Fold an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("fold-left"), using columns of m list elements as arguments for Goal.
include/3	Filter elements for which Goal succeeds.
maplist/2	True if Goal is successfully applied on all matching elements of the list.
maplist/3	True if Goal is successfully applied on all matching elements of the list.
maplist/4	True if Goal is successfully applied on all matching elements of the list.
maplist/5	True if Goal is successfully applied on all matching elements of the list.
partition/4	Filter elements of List according to Pred.
partition/5	Filter List according to Pred in three sets.
scanl/4	Scan an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("scan-left"), using columns of m list elements as arguments for Goal.
scanl/5	Scan an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("scan-left"), using columns of m list elements as arguments for Goal.
scanl/6	Scan an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("scan-left"), using columns of m list elements as arguments for Goal.
scanl/7	Scan an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("scan-left"), using columns of m list elements as arguments for Goal.
apply_macros.pl  -- Goal expansion rules to avoid meta-calling
arithmetic.pl  -- Extensible arithmetic
assoc.pl
assoc_to_keys/2	True if Keys is the list of keys in Assoc.
assoc_to_list/2	Translate Assoc to a list Pairs of Key-Value pairs.
assoc_to_values/2	True if Values is the list of values in Assoc.
del_assoc/4	True if Key-Value is in Assoc0.
del_max_assoc/4	True if Key-Value is in Assoc0 and Key is the greatest key.
del_min_assoc/4	True if Key-Value is in Assoc0 and Key is the smallest key.
empty_assoc/1	Is true if Assoc is the empty association list.
gen_assoc/3	True if Key-Value is an association in Assoc.
get_assoc/3	True if Key-Value is an association in Assoc.
get_assoc/5	True if Key-Val0 is in Assoc0 and Key-Val is in Assoc.
is_assoc/1	True if Assoc is an association list.
list_to_assoc/2	Create an association from a list Pairs of Key-Value pairs.
map_assoc/2	True if Pred(Value) is true for all values in Assoc.
map_assoc/3	Map corresponding values.
max_assoc/3	True if Key-Value is in Assoc and Key is the largest key.
min_assoc/3	True if Key-Value is in assoc and Key is the smallest key.
ord_list_to_assoc/2	Assoc is created from an ordered list Pairs of Key-Value pairs.
put_assoc/4	Assoc is Assoc0, except that Key is associated with Value.
atom.pl  -- Operations on atoms
backcomp.pl  -- Backward compatibility
base32.pl
base32/2	Translates between plaintext and base32 encoded atom or string.
base32/3	Encode/decode list of character codes using base32.
base64.pl
base64/2	Equivalent to base64_encoded/3 using the options as(atom) and encoding(iso_latin_1).
base64/3	Encode/decode list of character codes using base64.
base64_encoded/3	General the base64 encoding and decoding.
base64_encoded/4
base64url/2	Translates between plaintext and base64url encoded atom or string.
base64url/3	Encode/decode list of character codes using Base64URL.
broadcast.pl  -- Event service
charsio.pl  -- I/O on Lists of Character Codes
check.pl  -- Consistency checking
codesio.pl
format_to_codes/3	Use format/2 to write to a list of character codes.
format_to_codes/4	Use format/2 to write to a difference list of character codes.
open_codes_stream/2	Open Codes as an input stream.
read_from_codes/2	Read Codes into Term.
read_term_from_codes/3	Read Codes into Term.
with_output_to_codes/2	Run Goal with as once/1.
with_output_to_codes/3	Run Goal with as once/1.
with_output_to_codes/4	As with_output_to_codes/3, but Stream is unified with the temporary stream.
write_term_to_codes/3	True when Codes is a string that matches the output of write_term/3 using Options.
write_term_to_codes/4	True when Codes\Tail is a difference list containing the character codes that matches the output of write_term/3 using Options.
write_to_codes/2	Codes is a list of character codes produced by write/1 on Term.
write_to_codes/3	Codes is a difference-list of character codes produced by write/1 on Term.
coinduction.pl  -- Co-Logic Programming
csv.pl  -- Process CSV (Comma-Separated Values) data
ctypes.pl  -- Character code classification
is_digit/3	Succeeds if `C' is a digit using `Base' as base and `Weight' represents its value.
is_paren/2	True if Open is the open-parenthesis of Close.
to_lower/2	Downcase a character code.
to_upper/2	Upcase a character code.
upper_lower/2	True when U is the character code of an uppercase character and L is the character code of the corresponding lowercase character.
date.pl  -- Process dates and times
debug.pl
assertion_failed/2	This hook is called if the Goal of assertion/1 fails.
debug_print_hook/3	Hook called by debug/3.
assertion/1	Acts similar to C assert() macro.
debug/1	Add/remove a topic from being printed.
debug/3	Format a message if debug topic is enabled.
debug_message_context/1	Specify additional context for debug messages.
debugging/1	Examine debug topics.
debugging/2	Examine debug topics.
list_debug_topics/0	List currently known topics for debug/3 and their setting.
list_debug_topics/1	List currently known topics for debug/3 and their setting.
nodebug/1	Add/remove a topic from being printed.
dialect.pl  -- Support multiple Prolog dialects
dicts.pl
dict_fill/4	Implementation for the dicts_to_same_keys/3 OnEmpty closure that fills new cells with a copy of ValueIn.
dict_keys/2	True when Keys is an ordered set of the keys appearing in Dict.
dict_size/2	True when KeyCount is the number of keys in Dict.
dicts_join/3	Join dicts in Dicts that have the same value for Key, provided they do not have conflicting values on other keys.
dicts_join/4	Join two lists of dicts (Dicts1 and Dicts2) on Key.
dicts_same_keys/2	True if List is a list of dicts that all have the same keys and Keys is an ordered set of these keys.
dicts_same_tag/2	True when List is a list of dicts that all have the tag Tag.
dicts_slice/3	DictsOut is a list of Dicts only containing values for Keys.
dicts_to_compounds/4	True when Dicts and Compounds are lists of the same length and each element of Compounds is a compound term whose arguments represent the values associated with the corresponding keys in Keys.
dicts_to_same_keys/3	DictsOut is a copy of DictsIn, where each dict contains all keys appearing in all dicts of DictsIn.
mapdict/2	True when all dicts have the same set of keys and call(Goal, Key, V1, ...) is true for all keys in the dicts.
mapdict/3	True when all dicts have the same set of keys and call(Goal, Key, V1, ...) is true for all keys in the dicts.
mapdict/4	True when all dicts have the same set of keys and call(Goal, Key, V1, ...) is true for all keys in the dicts.
dif.pl
dif/2	Constraint that expresses that Term1 and Term2 never become identical (==/2).
edinburgh.pl  -- Some traditional Edinburgh predicates
edit.pl
edit/0	Edit associated or script file.
edit/1	Edit indicated object.
edit_command/2	This predicate should specify the shell-command called to invoke the user's editor.
locate/2	Locate object from the specified location.
locate/3
select_location/3
error.pl
exceptions.pl
catch/4	As catch/3, only catching exceptions for which exception(ErrorType,Ball) is true.
error_term/2	Describe the formal part of error(Formal,ImplDefined) exceptions.
exception/2	If Ball is unbound, adds a delayed goal that tests the error belongs to Type when Ball is instantiated (by catch/3).
exception_term/2	Describe exceptions that are not error(Formal, _) terms.
exception_type/2	Declare all exceptions subsumed by Term to be an exception of Type.
explain.pl
explain/1	Give an explanation on Term.
explain/2	True when Explanation is an explanation of Term.
gensym.pl
gensym/2	Generate <Base>1, <Base>2, etc atoms on each subsequent call.
reset_gensym/0	Reset gensym for all registered keys.
reset_gensym/1	Restart generation of identifiers from Base at <Base>1.
git.pl  -- Run GIT commands
hashtable.pl
ht_del/3	Delete Key-Value from HT.
ht_gen/3	True when Key-Value is in HT.
ht_get/3	True when Key is in HT and associated with Value.
ht_is_hashtable/1	True when HT is a hash table.
ht_keys/2	True when Keys is an ordered set of all keys in HT.
ht_new/1	Create a new hash table.
ht_pairs/2	True when Pairs and HT represent the same association.
ht_put/3	Add a Key-Value to HT.
ht_put/5	Add Key-Value to HT.
ht_put_new/3	As ht_put/3, but fails if Key is already in HT instead of updating the associated value.
ht_size/2	True when Size is the number of key-value pairs in HT.
ht_update/4	True when HT holds Key-Old before and Key-New after this call.
heaps.pl  -- heaps/priority queues
increval.pl
incr_directly_depends/2	True if Goal1 depends on Goal2 in the IDG.
incr_invalid_subgoals/1	List is a sorted list (set) of the incremental subgoals that are currently invalid.
incr_invalidate_call/1	This is the XSB name, but the manual says incr_invalidate_calls/1 and the comment with the code suggests this is misnamed.
incr_invalidate_calls/1	Invalidate all tables for subgoals of Goal as well as tables that are affected by these.
incr_is_invalid/1	True when Subgoal's table is marked as invalid.
incr_propagate_calls/1	Activate the monotonic answer propagation similarly to when a new fact is asserted for a monotonic dynamic predicate.
incr_table_update/0	Updated all invalid tables.
incr_trans_depends/2	True for each pair in the transitive closure of incr_directly_depends(G1, G2).
is_incremental_subgoal/1	This predicate non-deterministically unifies Subgoal with incrementally tabled subgoals that are currently table entries.
iostream.pl  -- Utilities to deal with streams
close_any/1	Execute the Close closure returned by open_any/5.
open_any/5	Establish a stream from Specification that should be closed using Close, which can either be called or passed to close_any/1.
lazy_lists.pl
lazy_engine_next/4	Lazy list iterator for engines.
lazy_findall/3	True when List is a lazy list containing the instantiations for Template for each answer of Goal.
lazy_findall/4	True when List is a lazy list containing the instantiations for Template for each answer of Goal.
lazy_get_codes/4	Lazy list iterator to get character codes from a stream.
lazy_list/2	Create a lazy list from a callback.
lazy_list/3	Create a lazy list where the next element is defined by.
lazy_list_iterator/4	Directive to create a lazy list iterator from a predicate that gets a single next value.
lazy_list_length/2	True if Len is the length of the materialized lazy list.
lazy_list_materialize/1	Materialize the lazy list.
lazy_message_queue/4	Lazy list iterator for message queues.
lazy_read_lines/4	Lazy list iterator to read lines from Stream.
lazy_read_terms/4	Turn a stream into a lazy list of Prolog terms.
listing.pl  -- List programs and pretty print clauses
listing/0	Lists all predicates defined in the calling module.
listing/1	List matching clauses.
listing/2	List matching clauses.
portray_clause/1	Portray `Clause' on the current output stream.
portray_clause/2	Portray `Clause' on the current output stream.
portray_clause/3	Portray `Clause' on the current output stream.
lists.pl
append/2	Concatenate a list of lists.
append/3	List1AndList2 is the concatenation of List1 and List2.
clumped/2	Pairs is a list of Item-Count pairs that represents the run length encoding of Items.
delete/3	Delete matching elements from a list.
flatten/2	Is true if FlatList is a non-nested version of NestedList.
intersection/3	True if Set3 unifies with the intersection of Set1 and Set2.
is_set/1	True if Set is a proper list without duplicates.
last/2	Succeeds when Last is the last element of List.
list_to_set/2	True when Set has the same elements as List in the same order.
max_list/2	True if Max is the largest number in List.
max_member/2	True when Max is the largest member in the standard order of terms.
max_member/3	True when Max is the largest member according to Pred, which must be a 2-argument callable that behaves like (@=<)/2.
member/2	True if Elem is a member of List.
min_list/2	True if Min is the smallest number in List.
min_member/2	True when Min is the smallest member in the standard order of terms.
min_member/3	True when Min is the smallest member according to Pred, which must be a 2-argument callable that behaves like (@=<)/2.
nextto/3	True if Y directly follows X in List.
nth0/3	True when Elem is the Index'th element of List.
nth0/4	Select/insert element at index.
nth1/3	Is true when Elem is the Index'th element of List.
nth1/4	As nth0/4, but counting starts at 1.
numlist/3	List is a list [Low, Low+1, ... High].
permutation/2	True when Xs is a permutation of Ys.
prefix/2	True iff Part is a leading substring of Whole.
proper_length/2	True when Length is the number of elements in the proper list List.
reverse/2	Is true when the elements of List2 are in reverse order compared to List1.
same_length/2	Is true when List1 and List2 are lists with the same number of elements.
select/3	Is true when List1, with Elem removed, results in List2.
select/4	Select from two lists at the same position.
selectchk/3	Semi-deterministic removal of first element in List that unifies with Elem.
selectchk/4	Semi-deterministic version of select/4.
subseq/3	Is true when SubList contains a subset of the elements of List in the same order and Complement contains all elements of List not in SubList, also in the order they appear in List.
subset/2	True if all elements of SubSet belong to Set as well.
subtract/3	Delete all elements in Delete from Set.
sum_list/2	Sum is the result of adding all numbers in List.
union/3	True if Set3 unifies with the union of the lists Set1 and Set2.
macros.pl
expand_macros/5	Perform macro expansion on TermIn with layout PosIn to produce TermOut with layout PosOut.
include_macros/3	Include macros from another module.
macro_position/1	True when Position is the position of the macro.
main.pl
argv_options/3	Parse command line arguments.
argv_options/4	As argv_options/3 in guided mode, Currently this version allows parsing argument options throwing an exception rather than calling halt/1 by passing an empty list to ParseOptions.
argv_usage/1	Use print_message/2 to print a usage message at Level.
cli_debug_opt_help/2	Implements opt_type/3, opt_help/2 and opt_meta/2 for debug arguments.
cli_debug_opt_meta/2	Implements opt_type/3, opt_help/2 and opt_meta/2 for debug arguments.
cli_debug_opt_type/3	Implements opt_type/3, opt_help/2 and opt_meta/2 for debug arguments.
cli_enable_development_system/0	Re-enable the development environment.
cli_parse_debug_options/2	Parse certain commandline options for debugging and development purposes.
main/0	Call main/1 using the passed command-line arguments.
make.pl  -- Reload modified source files
modules.pl  -- Module utility predicates
nb_set.pl
add_nb_set/2	Insert Key into the set.
add_nb_set/3	Insert Key into the set.
empty_nb_set/1	Create an empty non-backtrackable set.
gen_nb_set/2	Enumerate the members of a set in the standard order of terms.
nb_set_to_list/2	Get the elements of a an nb_set.
size_nb_set/2	Unify Size with the number of elements in the set.
occurs.pl  -- Finding and counting sub-terms
operators.pl
pop_operators/0	Revert all changes to the operator table realised since the last push_operators/1.
pop_operators/1	Reset operators as pushed by push_operators/2.
push_op/3	As op/3, but this call must appear between push_operators/1 and pop_operators/0.
push_operators/1	Installs the operators from New, where New is a list of op(Prec, Type, :Name).
push_operators/2	Installs the operators from New, where New is a list of op(Prec, Type, :Name).
option.pl  -- Option list processing
optparse.pl  -- command line parsing
ordsets.pl  -- Ordered set manipulation
oset.pl  -- Ordered set manipulation
pairs.pl
group_pairs_by_key/2	Group values with equivalent (==/2) consecutive keys.
map_list_to_pairs/3	Create a Key-Value list by mapping each element of List.
pairs_keys/2	Remove the values from a list of Key-Value pairs.
pairs_keys_values/3	True if Keys holds the keys of Pairs and Values the values.
pairs_values/2	Remove the keys from a list of Key-Value pairs.
transpose_pairs/2	Swap Key-Value to Value-Key.
persistency.pl  -- Provide persistent dynamic predicates
pio.pl  -- Pure I/O
portray_text.pl
portray_text/1	Switch portraying on or off.
set_portray_text/2	Set options for portraying.
set_portray_text/3	Set options for portraying.
pprint.pl  -- Pretty Print Prolog terms
predicate_options.pl  -- Access and analyse predicate options
prolog_autoload.pl
autoload_all/0	Force all necessary autoloading to be done now.
autoload_all/1	Force all necessary autoloading to be done now.
prolog_breakpoints.pl  -- Manage Prolog break-points
prolog_clause.pl
prolog_code.pl  -- Utilities for reasoning about code
prolog_codewalk.pl  -- Prolog code walker
prolog_colour.pl  -- Prolog syntax colouring support.
prolog_config.pl  -- Provide configuration information
prolog_debug.pl  -- User level debugging tools
debug_control_hook/1	Allow user-hooks in the Prolog debugger interaction.
debugging/0	Report current status of the debugger.
debugging_hook/1	Multifile hook that is called as forall(debugging_hook(DebugMode), true) and that may be used to extend the information printed from other debugging libraries.
exception_hook/5	Trap exceptions and consider whether or not to start the tracer.
nospy/1	Set/clear spy-points.
nospyall/0	Set/clear spy-points.
notrap/1	Install a trap on error(Formal, Context) exceptions that unify.
spy/1	Set/clear spy-points.
trap/1	Install a trap on error(Formal, Context) exceptions that unify.
trap_alias/2	Define short hands for commonly used exceptions.
prolog_format.pl  -- Analyse format specifications
prolog_history.pl  -- Per-directory persistent commandline history
prolog_jiti.pl  -- Just In Time Indexing (JITI) utilities
prolog_metainference.pl  -- Infer meta-predicate properties
prolog_pack.pl  -- A package manager for Prolog
prolog_source.pl  -- Examine Prolog source-files
prolog_stack.pl  -- Examine the Prolog stack
prolog_versions.pl  -- Demand specific (Prolog) versions
prolog_wrap.pl
current_predicate_wrapper/4	True if Head is wrapped with Body.
unwrap_predicate/2	Remove the outermost wrapper whose name unifies with Name.
wrap_predicate/4	Wrap the predicate referenced by Head using Body.
prolog_xref.pl  -- Prolog cross-referencer data collection
pure_input.pl  -- Pure Input from files and streams
qsave.pl  -- Save current program as a state or executable
quasi_quotations.pl  -- Define Quasi Quotation syntax
random.pl
getrand/1	Query/set the state of the random generator.
maybe/0	Succeed/fail with equal probability (variant of maybe/1).
maybe/1	Succeed with probability P, fail with probability 1-P.
maybe/2	Succeed with probability K/N (variant of maybe/1).
random/1	Binds R to a new random float in the open interval (0.0,1.0).
random/3	Generate a random integer or float in a range.
random_between/3	Binds R to a random integer in [L,U] (i.e., including both L and U).
random_member/2	X is a random member of List.
random_numlist/4	Unify List with an ascending list of integers between L and U (inclusive).
random_perm2/4	Does X=A,Y=B or X=B,Y=A with equal probability.
random_permutation/2	Permutation is a random permutation of List.
random_select/3	Randomly select or insert an element.
random_subseq/3	Selects a random subsequence Subseq of List, with Complement containing all elements of List that were not selected.
randseq/3	S is a list of K unique random integers in the range 1..N.
randset/3	S is a sorted list of K unique random integers in the range 1..N.
setrand/1	Query/set the state of the random generator.
rbtrees.pl
is_rbtree/1	True if Term is a valid Red-Black tree.
list_to_rbtree/2	Tree is the red-black tree corresponding to the mapping in List, which should be a list of Key-Value pairs.
ord_list_to_rbtree/2	Tree is the red-black tree corresponding to the mapping in list List, which should be a list of Key-Value pairs.
rb_apply/4	If the value associated with key Key is Val0 in Tree, and if call(G,Val0,ValF) holds, then NewTree differs from Tree only in that Key is associated with value ValF in tree NewTree.
rb_clone/3	`Clone' the red-back tree TreeIn into a new tree TreeOut with the same keys as the original but with all values set to unbound values.
rb_del_max/4	Delete the largest element from the tree Tree, returning the key Key, the value Val associated with the key and a new tree NewTree.
rb_del_min/4	Delete the least element from the tree Tree, returning the key Key, the value Val associated with the key and a new tree NewTree.
rb_delete/3	Delete element with key Key from the tree Tree, returning the value Val associated with the key and a new tree NewTree.
rb_delete/4	Same as rb_delete(Tree, Key, NewTree), but also unifies Val with the value associated with Key in Tree.
rb_empty/1	Succeeds if Tree is an empty Red-Black tree.
rb_fold/4	Fold the given predicate over all the key-value pairs in Tree, starting with initial state State0 and returning the final state State.
rb_in/3	True when Key-Value is a key-value pair in red-black tree Tree.
rb_insert/4	Add an element with key Key and Value to the tree Tree creating a new red-black tree NewTree.
rb_insert_new/4	Add a new element with key Key and Value to the tree Tree creating a new red-black tree NewTree.
rb_keys/2	Keys is unified with an ordered list of all keys in the Red-Black tree Tree.
rb_lookup/3	True when Value is associated with Key in the Red-Black tree Tree.
rb_map/2	True if call(Goal, Value) is true for all nodes in T.
rb_map/3	For all nodes Key in the tree Tree, if the value associated with key Key is Val0 in tree Tree, and if call(G,Val0,ValF) holds, then the value associated with Key in NewTree is ValF.
rb_max/3	Key is the maximal key in Tree, and is associated with Val.
rb_min/3	Key is the minimum key in Tree, and is associated with Val.
rb_new/1	Create a new Red-Black tree Tree.
rb_next/4	Next is the next element after Key in Tree, and is associated with Val.
rb_partial_map/4	For all nodes Key in Keys, if the value associated with key Key is Val0 in tree Tree, and if call(G,Val0,ValF) holds, then the value associated with Key in NewTree is ValF, otherwise it is the value associated with the key in Tree.
rb_previous/4	Previous is the previous element after Key in Tree, and is associated with Val.
rb_size/2	Size is the number of elements in Tree.
rb_update/4	Tree NewTree is tree Tree, but with value for Key associated with NewVal.
rb_update/5	Same as rb_update(Tree, Key, NewVal, NewTree) but also unifies OldVal with the value associated with Key in Tree.
rb_visit/2	Pairs is an infix visit of tree Tree, where each element of Pairs is of the form Key-Value.
readutil.pl  -- Read utilities
record.pl  -- Access compound arguments by name
rwlocks.pl
with_rwlock/3	Run Goal, synchronized with LockId in ModeSpec.
with_rwlock/4	Run Goal, synchronized with LockId in ModeSpec.
sandbox.pl  -- Sandboxed Prolog code
settings.pl  -- Setting management
shlib.pl  -- Utility library for loading foreign objects (DLLs, shared objects)
solution_sequences.pl  -- Modify solution sequences
sort.pl
locale_sort/2	Sort a list of atoms using the current locale.
predsort/3	Sorts similar to sort/2, but determines the order of two terms by calling Compare(-Delta, +E1, +E2).
statistics.pl  -- Get information about resource usage
streams.pl  -- Manage Prolog streams
strings.pl  -- String utilities
system.pl  -- System utilities
tables.pl  -- XSB interface to tables
terms.pl  -- Term manipulation
thread.pl  -- High level thread primitives
thread_pool.pl  -- Resource bounded thread management
threadutil.pl  -- Interactive thread utilities
ugraphs.pl  -- Graph manipulation library
url.pl
file_name_to_url/2	Translate between a filename and a file:// URL.
global_url/3	Translate a possibly relative URL into an absolute one.
http_location/2	Construct or analyze an HTTP location.
is_absolute_url/1	True if URL is an absolute URL.
parse_url/2	Construct or analyse a URL.
parse_url/3	Similar to parse_url/2 for relative URLs.
parse_url_search/2	Construct or analyze an HTTP search specification.
set_url_encoding/2	Query and set the encoding for URLs.
url_iri/2	Convert between a URL, encoding in US-ASCII and an IRI.
www_form_encode/2	En/decode to/from application/x-www-form-encoded.
utf8.pl
utf8_codes/3	DCG translating between a Unicode code-list and its UTF-8 encoded byte-string.
varnumbers.pl  -- Utilities for numbered terms
wfs.pl  -- Well Founded Semantics interface
when.pl  -- Conditional coroutining
writef.pl
swritef/2	Use writef/1 or writef/2 and write the result to a string.
swritef/3	Use writef/1 or writef/2 and write the result to a string.
writef/1	Formatted write to the current_output.
writef/2	Formatted write to the current_output.
www_browser.pl  -- Open a URL in the users browser
yall.pl  -- Lambda expressions
zip.pl  -- Access resource ZIP archives