Planar Sublattices of a Free Lattice. II
Planar Sublattices of a Free Lattice. II
In Planar sublattices of a free lattice, I [ 8 ] we verify Jonsson's conjecture for finite planar lattices; in particular we obtain a characterization of finite planar sublattices of a free lattice among all finite lattices. In the present paper we use arguments of a quite different flavour to …