/- Copyright 2025 The Formal Conjectures Authors. 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 https://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. -/ import FormalConjectures.ErdosProblems.«508»

The Hadwiger-Nelson Problem

The Hadwiger-Nelson problem asks for the minimum number of colors required to color the plane such that no two points at unit distance from each other have the same color.

Reference: Wikipedia

This file points to the canonical formalization in FormalConjectures.ErdosProblems.«508».