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This file is part of Logtalk https://logtalk.org/ SPDX-FileCopyrightText: 1998-2023 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.

To load this example and for sample queries, please see the SCRIPT.txt file.

This example illustrates the use of assignable variables and parametric objects as alternative implementation to dynamic object predicates for storing (backtrackable) object state. For more information on assignable variables please consult the URL:

http://www.kprolog.com/en/logical_assignment/

The objects in this example make use of the library category assignvars. This category contains an adaptation of the pure logical subset implementation of assignable variables by Nobukuni Kino, which can be found on the URL above.