The inverse of a Tr-lattice need not be a Tr-lattice


Dragan M. Acketa




A Tr-lattice is a finite lattice $L$ with the following property: if $L$ is isomorphic to the lattice of cyclic fiats of a matrold $M$, then $M$ is transversal. In this paper we give an example of a Tr-lattice Lt such that the Inverse lattice $L^{-1}$ is not a Tr-lattice.