The complexity of the Hajós calculus
T Pitassi, A Urquhart - SIAM Journal on Discrete Mathematics, 1995 - SIAM
The Hajós calculus is a simple, nondeterministic procedure that generates the class of non-3-
colorable graphs. Mansfield and Welsch posed the question of whether there exist graphs …
colorable graphs. Mansfield and Welsch posed the question of whether there exist graphs …