---

jupyter: jupytext: text_representation: extension: .md format_name: markdown format_version: '1.3' jupytext_version: 1.16.7 kernelspec: display_name: Logtalk language: logtalk name: logtalk_kernel ---

<!--

This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2025 Paulo Moura <pmoura@logtalk.org> SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. -->

This folder contains a set of simple examples illustrating how to use Markus Triska's CLP(FD) library distributed with SWI-Prolog with Logtalk. These examples are adapted with permission from the original author, Markus Triska.

The CLP(FD) library is loaded from the loader.lgt auxiliary loader file. This library must always be loaded prior to compilation of the individual example files.

Print Logtalk, Prolog backend, and kernel versions (if running as a notebook):

%versions

Start by loading the example:

logtalk_load(clp_swipl(loader)).

Change the default term writing depth:

set_prolog_flag(answer_write_options, [quoted(true), portray(true), max_depth(50), priority(699)]).

<!-- true. -->

puzzle::solve(Sum=Rs).

<!-- Sum = [9, 5, 6, 7]+[1, 0, 8, 5], Rs = [1, 0, 6, 5, 2] . -->

hexagon::mhex(Vs).

<!-- Vs = [3, 17, 18, 19, 7, 1, 11, 16, 2, 5, 6, 9, 12, 4, 8, 14, 10, 13, 15] ; Vs = [3, 19, 16, 17, 7, 2, 12, 18, 1, 5, 4, 10, 11, 6, 8, 13, 9, 14, 15] ; Vs = [9, 11, 18, 14, 6, 1, 17, 15, 8, 5, 7, 3, 13, 4, 2, 19, 10, 12, 16] ; (etc) -->

soduku::sudoku(Rows), append(Rows, Vs), label(Vs).

<!-- Rows = [[1, 2, 3, 4, 5, 6, 7, 8, 9], [4, 5, 6, 7, 8, 9, 1, 2, 3], [7, 8, 9, 1, 2, 3, 4, 5, 6], [2, 1, 4, 3, 6, 5, 8, 9, 7], [3, 6, 5, 8, 9, 7, 2, 1, 4], [8, 9, 7, 2, 1, 4, 3, 6, 5], [5, 3, 1, 6, 4, 2, 9, 7, 8], [6, 4, 2, 9, 7, 8, 5, 3, 1], [9, 7, 8, 5, 3, 1, 6, 4, 2]], Vs = [1, 2, 3, 4, 5, 6, 7, 8, 9, 4, 5, 6, 7, 8, 9, 1, 2, 3, 7, 8, 9, 1, 2, 3, 4, 5, 6, 2, 1, 4, 3, 6, 5, 8, 9, 7, 3, 6, 5, 8, 9, 7, 2, 1, 4, 8, 9, 7, 2|...] ; Rows = [[1, 2, 3, 4, 5, 6, 7, 8, 9], [4, 5, 6, 7, 8, 9, 1, 2, 3], [7, 8, 9, 1, 2, 3, 4, 5, 6], [2, 1, 4, 3, 6, 5, 8, 9, 7], [3, 6, 5, 8, 9, 7, 2, 1, 4], [8, 9, 7, 2, 1, 4, 3, 6, 5], [5, 3, 1, 6, 4, 2, 9, 7, 8], [6, 4, 8, 9, 7, 1, 5, 3, 2], [9, 7, 2, 5, 3, 8, 6, 4, 1]], Vs = [1, 2, 3, 4, 5, 6, 7, 8, 9, 4, 5, 6, 7, 8, 9, 1, 2, 3, 7, 8, 9, 1, 2, 3, 4, 5, 6, 2, 1, 4, 3, 6, 5, 8, 9, 7, 3, 6, 5, 8, 9, 7, 2, 1, 4, 8, 9, 7, 2|...] ; (etc) -->

soduku::(problem(1, Rows), sudoku(Rows)), append(Rows, Vs), label(Vs).

<!-- Rows = [[1, 5, 6, 8, 9, 4, 3, 2, 7], [9, 2, 8, 7, 3, 1, 4, 5, 6], [4, 7, 3, 2, 6, 5, 9, 1, 8], [3, 6, 2, 4, 1, 7, 8, 9, 5], [7, 8, 9, 3, 5, 2, 6, 4, 1], [5, 1, 4, 9, 8, 6, 2, 7, 3], [8, 3, 1, 5, 4, 9, 7, 6, 2], [6, 9, 7, 1, 2, 3, 5, 8, 4], [2, 4, 5, 6, 7, 8, 1, 3, 9]], Vs = [1, 5, 6, 8, 9, 4, 3, 2, 7, 9, 2, 8, 7, 3, 1, 4, 5, 6, 4, 7, 3, 2, 6, 5, 9, 1, 8, 3, 6, 2, 4, 1, 7, 8, 9, 5, 7, 8, 9, 3, 5, 2, 6, 4, 1, 5, 1, 4, 9|...] . -->

The following two queries implies that Ghostscript is available from the command-line (skip if running as a notebook):

(current_object(jupyter) -> true; soduku::(problem(1, Rows), show([ff], Rows))).

<!-- Rows = [[1, 5, 6, 8, 9, 4, 3, 2, 7], [9, 2, 8, 7, 3, 1, 4, 5, 6], [4, 7, 3, 2, 6, 5, 9, 1, 8], [3, 6, 2, 4, 1, 7, 8, 9, 5], [7, 8, 9, 3, 5, 2, 6, 4, 1], [5, 1, 4, 9, 8, 6, 2, 7, 3], [8, 3, 1, 5, 4, 9, 7, 6, 2], [6, 9, 7, 1, 2, 3, 5, 8, 4], [2, 4, 5, 6, 7, 8, 1, 3, 9]] . -->

(current_object(jupyter) -> true; soduku::show([ff], Rows)).

<!-- Rows = [[1, 2, 3, 4, 5, 6, 7, 8, 9], [4, 5, 6, 7, 8, 9, 1, 2, 3], [7, 8, 9, 1, 2, 3, 4, 5, 6], [2, 3, 1, 6, 7, 4, 8, 9, 5], [8, 7, 5, 9, 1, 2, 3, 6, 4], [6, 9, 4, 5, 3, 8, 2, 1, 7], [3, 1, 7, 2, 6, 5, 9, 4, 8], [5, 4, 2, 8, 9, 7, 6, 3, 1], [9, 6, 8, 3, 4, 1, 5, 7, 2]] ; Rows = [[1, 2, 3, 4, 5, 6, 7, 8, 9], [4, 5, 6, 7, 8, 9, 1, 2, 3], [7, 8, 9, 1, 2, 3, 4, 5, 6], [2, 3, 1, 6, 7, 4, 8, 9, 5], [8, 7, 5, 9, 1, 2, 3, 6, 4], [6, 9, 4, 5, 3, 8, 2, 1, 7], [3, 1, 7, 2, 6, 5, 9, 4, 8], [5, 4, 8, 3, 9, 1, 6, 7, 2], [9, 6, 2, 8, 4, 7, 5, 3, 1]] ; Rows = [[1, 2, 3, 4, 5, 6, 7, 8, 9], [4, 5, 6, 7, 8, 9, 1, 2, 3], [7, 8, 9, 1, 2, 3, 4, 5, 6], [2, 3, 1, 6, 7, 4, 8, 9, 5], [8, 7, 5, 9, 1, 2, 3, 6, 4], [6, 9, 4, 5, 3, 8, 2, 1, 7], [3, 1, 7, 2, 6, 5, 9, 4, 8], [9, 6, 2, 8, 4, 7, 5, 3, 1], [5, 4, 8, 3, 9, 1, 6, 7, 2]] ; (etc) -->

queens::n_queens(8, Qs), labeling([ff], Qs).

<!-- Qs = [1, 5, 8, 6, 3, 7, 2, 4] ; Qs = [1, 6, 8, 3, 7, 4, 2, 5] ; Qs = [1, 7, 4, 6, 8, 2, 5, 3] ; (etc) -->

The following queries require that Ghostscript is available from the command-line (skip if running as a notebook):

(current_object(jupyter) -> true; queens::show(8, [ff], Qs)).

<!-- Qs = [1, 5, 8, 6, 3, 7, 2, 4] ; Qs = [1, 6, 8, 3, 7, 4, 2, 5] ; Qs = [1, 7, 4, 6, 8, 2, 5, 3] ; (etc) -->

(current_object(jupyter) -> true; queens::show(N, [ff], Qs)).

<!-- N = 1, Qs = [1] ; N = 4, Qs = [2, 4, 1, 3] ; N = 4, Qs = [3, 1, 4, 2] ; N = 5, Qs = [1, 3, 5, 2, 4] ; (etc) -->

oneground::oneground(X, Y, Z), Y = 5.

<!-- Y = 5, Z = 1, X in inf..sup. -->

knight::n_tour(N, Ts), meta::map(clpfd:label, Ts).

<!-- N = 0, Ts = [] ; N = 6, Ts = [[9, 10, 7, 8, 16, 17], [15, 19, 5, 6, 3, 4], [2, 1, 26, 12, 21, 29], [32, 31, 25, 18, 34, 11], [14, 13, 35, 36, 33, 22], [27, 28, 20, 30, 24, 23]] . -->

knight::n_tour(6, Ts), meta::map(label, Ts), knight::tour_enumeration(Ts, Es), meta::map(format("~t~w~3|~t~w~6|~t~w~9|~t~w~12|~t~w~15|~t~w~18|\n"), Es).

<!-- 1 30 25 6 3 32 26 7 2 31 24 5 29 36 27 4 33 16 8 19 34 15 12 23 35 28 21 10 17 14 20 9 18 13 22 11 Ts = [[9, 10, 7, 8, 16, 17], [15, 19, 5, 6, 3, 4], [2, 1, 26, 12, 21, 29], [32, 31, 25, 18, 34, 11], [14, 13, 35, 36, 33, 22], [27, 28, 20, 30, 24, 23]], Es = [[1, 30, 25, 6, 3, 32], [26, 7, 2, 31, 24, 5], [29, 36, 27, 4, 33, 16], [8, 19, 34, 15, 12, 23], [35, 28, 21, 10, 17, 14], [20, 9, 18, 13, 22, 11]] . -->

time((knight::n_tour(8, Ts), list::append(Ts, Vs), clpfd:labeling([ff], Vs))).

<!-- % 18,438,711 inferences, 4.230 CPU in 4.482 seconds (94% CPU, 4359033 Lips) Ts = [[11, 12, 18, 10, 15, 21, 13, 14], [3, 20, 17, 27, 23, 31, 30, 6], [2, 1, 29, 5, 4, 37, 8, 7], [19, 9, 33, 38, 35, 36, 16, 22], [43, 28, 50, 51, 52, 32, 24, 46], [26, 25, 53, 59, 55, 61, 62, 54], [34, 60, 57, 58, 63, 64, 40, 39], [42, 41, 49, 45, 44, 56, 48, 47]], Vs = [11, 12, 18, 10, 15, 21, 13, 14, 3, 20, 17, 27, 23, 31, 30, 6, 2, 1, 29, 5, 4, 37, 8, 7, 19, 9, 33, 38, 35, 36, 16, 22, 43, 28, 50, 51, 52, 32, 24, 46, 26, 25, 53, 59, 55, 61, 62, 54, 34|...]. -->

knight::n_tour(8, Ts), list::append(Ts, Vs), clpfd:labeling([ff], Vs), knight::tour_enumeration(Ts, Es), meta::map(format("~t~w~3|~t~w~6|~t~w~9|~t~w~12|~t~w~15|~t~w~18|~t~w~21|~t~w~24|\n"), Es).

<!-- 1 4 63 28 31 26 19 22 62 29 2 5 20 23 32 25 3 64 39 30 27 56 21 18 38 61 6 53 40 33 24 55 7 52 41 34 57 54 17 46 60 37 8 49 44 47 14 11 51 42 35 58 9 12 45 16 36 59 50 43 48 15 10 13 Ts = [[11, 12, 18, 10, 15, 21, 13, 14], [3, 20, 17, 27, 23, 31, 30, 6], [2, 1, 29, 5, 4, 37, 8, 7], [19, 9, 33, 38, 35, 36, 16, 22], [43, 28, 50, 51, 52, 32, 24, 46], [26, 25, 53, 59, 55, 61, 62, 54], [34, 60, 57, 58, 63, 64, 40, 39], [42, 41, 49, 45, 44, 56, 48, 47]], Vs = [11, 12, 18, 10, 15, 21, 13, 14, 3, 20, 17, 27, 23, 31, 30, 6, 2, 1, 29, 5, 4, 37, 8, 7, 19, 9, 33, 38, 35, 36, 16, 22, 43, 28, 50, 51, 52, 32, 24, 46, 26, 25, 53, 59, 55, 61, 62, 54, 34|...], Es = [[1, 4, 63, 28, 31, 26, 19, 22], [62, 29, 2, 5, 20, 23, 32, 25], [3, 64, 39, 30, 27, 56, 21, 18], [38, 61, 6, 53, 40, 33, 24, 55], [7, 52, 41, 34, 57, 54, 17, 46], [60, 37, 8, 49, 44, 47, 14, 11], [51, 42, 35, 58, 9, 12, 45, 16], [36, 59, 50, 43, 48, 15, 10, 13]] . -->

The following queries require that Ghostscript is available from the command-line (skip if running as a notebook):

(current_object(jupyter) -> true; knight::n_tour(6, Ts), meta::map(clpfd:label, Ts), knight::show(Ts)).

(current_object(jupyter) -> true; knight::n_tour(8, Ts), meta::map(clpfd:label, Ts), knight::show(Ts)).