Hadwiger number always upper bounds the chromatic number -- 1852-1943 -- A far-reaching generalisation of Guthrie's postulate

T Srinivasa Murthy

In a simple graph $G$, we prove that the \textit{Hadwiger number}, $h(G)$, of the given graph $G$ always upper bounds the \textit{chromatic number}, $\chi (G)$, of the given graph $G$,…