2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/222658We confirm the equitable $Δ$-coloring conjecture for interval graphs and establish the monotonicity of equitable colorability for them. We further obtain results on equitable colorability about square (or Cartesian) and cross (or direct) products of graphs.11 pages, Festschrift in honor of Man Keung SiuCombinatorics05C15text