Prolog Predicates

folgende Predicates werden vom Prolog Interpreter von Haus aus unterstützt:

Built-in predicates

Control Constructs

!/0 – Cut.
,/2 – Conjunction.
->/2 – If-Then.
->;/3 – If-Then-Else.
;/2 – Disjunction.
call/1 – Invoke a callable term as a goal.
call/2 – Invoke a callable term as a goal with an extra argument.
call/3 – Invoke a callable term as a goal with two extra arguments.
call/4 – Invoke a callable term as a goal with three extra arguments.
call/5 – Invoke a callable term as a goal with four extra arguments.
call/6 – Invoke a callable term as a goal with five extra arguments.
call/7 – Invoke a callable term as a goal with six extra arguments.
call/8 – Invoke a callable term as a goal with seven extra arguments.
catch/3 – Enable recovery from exceptions.
fail/0 – Always fail.
false/0 – Always fail.
throw/1 – Raise an exception.
true/0 – Always succeed.

Term Unification

=/2 – Unification.
subsumes_term/2 – Checks if general term can be made equivalent to specific one.
unify_with_occurs_check/2 – Check if two terms are unifiable.
\=/2 – Not unification.

Clause Creation and Destruction

abolish/1 – Remove all the clauses of a predicate.
asserta/1 – Add term to the Prolog database.
assertz/1 – Add term to the Prolog database.
retract/1 – Delete term from Prolog database.
retractall/1 – Removes rules and clauses which unify with a term.

Clause Retrieval and Information

clause/2 – Check the existence of rules.
current_predicate/1 – Check the existence of predicates.

Term Creation and Decomposition

=../2 – Check the descomposition of a term.
arg/3 – Check the argument of a term in the nth position.
copy_term/2 – Copy one term without bounding the variables on it.
functor/3 – Check characteristics of a term.
term_variables/2 – Get variables of term.

Term Comparison

==/2 – Term identical.
@</2 – Term less than.
@=</2 – Term less than or equal to.
@>/2 – Term greater than.
@>=/2 – Term greater than or equal to.
compare/3 – Compare two terms according to order.
\==/2 – Term not identical.

Type Testing

acyclic_term/1 – Check if term has no cycles.
atom/1 – Check if atom.
atomic/1 – Check if atom, integer or float.
callable/1 – Check if term is callable.
compound/1 – Check if compound.
float/1 – Check if float.
ground/1 – Check if term has no free variables.
integer/1 – Check if integer.
is_list/1 – Check if list.
nonvar/1 – Check if not variable.
number/1 – Check if integer or float.
var/1 – Check if variable.

Logic and Control

once/1 – Evaluate a term just once.
repeat/0 – Provide infinite choice points.
\+/1 – Not provable.

Atom Processing

atomic_list_concat/2 – Concatenate elements of list.
atomic_list_concat/3 – Concatenate elements of list with atom.
atom_chars/2 – Express an atom as a list of one character atoms.
atom_codes/2 – Express an atom as a list of character codes.
atom_concat/3 – Concatenate characters.
atom_length/2 – Length of an atom.
char_code/2 – Character code of an atom.
downcase_atom/2 – Turn atom into lowercase.
number_chars/2 – Express a number as a list of one character atoms.
number_codes/2 – Express a number as a list of number codes.
sub_atom/5 – Look for subatoms inside an atom.
upcase_atom/2 – Turn atom into uppercase.

All Solutions

bagof/3 – Find all the values that would make a goal succeed and structure them.
findall/3 – Find all the values that would make a goal succeed.
forall/2 – Check an action for all alternative bindings.
setof/3 – Find all the values that would make a goal succeed and organize and order them.

Arithmetic Evaluation

between/3 – Check if value is within a range of integers.
is/2 – Evaluate expression.
succ/2 – Return the successor of a positive number.

Arithmetic Comparison

</2 – Arithmetic less than.
=:=/2 – Arithmetic equal.
=</2 – Arithmetic less than or equal to.
=\=/2 – Arithmetic not equal.
>/2 – Arithmetic greater than.
>=/2 – Arithmetic greater than or equal to.

Implementation defined hooks

current_prolog_flag/2 – Check prolog flag and flag values.
halt/0 – Terminate a Prolog processor.
halt/1 – Terminate a Prolog processor and return message.
set_prolog_flag/2 – Set value of flag.

Input and Output

current_op/3 – Check properties of operator.
op/3 – Alter the operator table.

Stream Selection and Control

at_end_of_stream/0 – Check if last character from current input stream has been read.
at_end_of_stream/1 – Check if last character from a specific input stream has been read.
close/1 – Close a stream.
close/2 – Close a stream according to several options.
current_input/1 – Get the current input stream.
current_output/1 – Get the current output stream.
flush_output/0 – Flush output on current stream.
flush_output/1 – Flush output on specified stream.
open/3 – Open a source in a certain mode through a stream.
open/4 – Open a source in a certain mode through a stream according to some options.
set_input/1 – Set the current input stream.
set_output/1 – Set the current output stream.
set_stream_position/2 – Set the stream position.
stream_property/2 – Retrieve stream properties.

Character Input/Output

get_char/1 – Get character from current input stream.
get_char/2 – Get character from input stream.
get_code/1 – Get character code from current input stream.
get_code/2 – Get character code from input stream.
nl/0 – Write new line character to current output stream.
nl/1 – Write new line character to output stream.
peek_char/1 – Read character from current input stream without removing it.
peek_char/2 – Read character from input stream without removing it.
peek_code/1 – Read character code from current input stream without removing it.
peek_code/2 – Read character code from input stream without removing it.
put_char/1 – Write character in current output stream.
put_char/2 – Write character in output stream.
put_code/1 – Write character code in current output stream.
put_code/2 – Write character code in output stream.

Byte Input/Output

get_byte/1 – Read byte from current input stream.
get_byte/2 – Read byte fom input stream.
peek_byte/1 – Read byte from current input stream without removing it.
peek_byte/2 – Read byte from input stream without removing it.
put_byte/1 – Write byte in current output stream.
put_byte/2 – Write byte in output stream.

Term Input/Output

read/1 – Read Prolog term from current input stream.
read/2 – Read Prolog term from input stream.
read_term/2 – Read Prolog term from current input stream according to some options.
read_term/3 – Read Prolog term from input stream according to some options.
write/1 – Write Prolog term to current output stream.
write/2 – Write Prolog term to output stream.
writeq/1 – Write Prolog term to current output stream, quoting atoms if necessary.
writeq/2 – Write Prolog term to output stream, quoting atoms if necessary.
write_canonical/1 – Write Prolog term to current output stream in canonical form.
write_canonical/2 – Write Prolog term to output stream in canonical form.
write_term/2 – Write Prolog term into current output stream according to some options.
write_term/3 – Write Prolog term into output stream according to some options.