Characterizations of Finite Lattices that are Bounded-Homomqrphic Images or Sublattices of Free Lattices
Alan Day · Canadian Journal of Mathematics · 1979
In [8], McKenzie introduced the notion of a bounded homomorphism between lattices, and, using this concept, proved several deep results in lattice theory. Some of these results were intimately connected with the work of Jónsson and Kiefer in [6] where an attempt was made to characterize finite sublattices of free lattices. McKenzie's characterization and others that followed (see [7] and [5]) still have not answered the (now) celebrated Jônsson conjecture: A finite lattice is a sublattice of a free lattice if and only if it satisfies (SD∨), (SD∨) and (W). (The properties mentioned here are defined in the text.)