Quasivarieties of Graphs and Independent Axiomatizability
A. V. Kravchenko, A. V. Yakovlev · Siberian Advances in Mathematics · 2018
In the present article, we continue to study the complexity of the lattice of quasivarieties of graphs. For every quasivariety K of graphs that contains a non-bipartite graph, we find a subquasivariety K ′ ⊆ K such that there exist 2 ω subquasivarieties K ″ ∈ L q ( K ′) without covers (hence, without independent bases for their quasi-identities in K ′).