Lattices of subclasses
М. V. Schwidefsky, Anna Zamojska-Dzienio · Siberian Mathematical Journal · 2012
We investigate the structure of lattices of subclasses of different types; among those are relative sub(quasi)variety lattices as well as relative (finitary) subprevariety lattices. Among other results, we prove a reduction theorem for (finitary) subprevariety lattices which generalizes a result of V. A. Gorbunov. We also answer a question by D. E. Pal-chunov and provide some noncomputability properties of lattices of relative subclasses.