#!/usr/bin/env python3
# Copyright 2010-2021 Google LLC
# 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.
"""Simple model with a reified constraint."""

from ortools.sat.python import cp_model


def ReifiedSampleSat():
    """Showcase creating a reified constraint."""
    model = cp_model.CpModel()

    x = model.NewBoolVar('x')
    y = model.NewBoolVar('y')
    b = model.NewBoolVar('b')

    # First version using a half-reified bool and.
    model.AddBoolAnd(x, y.Not()).OnlyEnforceIf(b)

    # Second version using implications.
    model.AddImplication(b, x)
    model.AddImplication(b, y.Not())

    # Third version using bool or.
    model.AddBoolOr(b.Not(), x)
    model.AddBoolOr(b.Not(), y.Not())


ReifiedSampleSat()
