Four colour problem | Four color problem (Angielski)
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Definicja wiek 14 lat poziom 2
The problem which asks whether there exists any network of lines and points in a plane which requires more than four colours in order to colour it in such a way that adjacent regions always have different colours.
In 1976 it was proved that four colours is always sufficient to do this, but the proof involved using a computer to check a large number of possible small networks - it would have taken too long for a human to check the proof, so some mathematicians feel that this proof is not acceptable.
On different kinds of surfaces the number of colours required is different. On the surface of a torus it is seven.
In 1976 it was proved that four colours is always sufficient to do this, but the proof involved using a computer to check a large number of possible small networks - it would have taken too long for a human to check the proof, so some mathematicians feel that this proof is not acceptable.
On different kinds of surfaces the number of colours required is different. On the surface of a torus it is seven.
Relacje
- Pojęcia ogólniejsze:
- (en) Graph in graph theory
- Pojęcie opiera się na:
- (en) Graph theory
- (en) Seven colour theorem
- Zobacz również:
- (en) Four colour theorem
Ufundowana przez: EU Socrates Minerva, HeyMath!, Cambridge University Press