Christian Herrmann

activity

20192025

collaborators

Showing 2024Show all

3 papers · 1 filter

math.CO2024

S-Glued sums of lattices

Christian Herrmann, Dale R. Worley

For many equation-theoretical questions about modular lattices, Hall and Dilworth give a useful construction: Let $L_{0}$ be a lattice with largest element $u_{0}$ , $L_{1}$ be a lattice…

math.RA2024

Direct finiteness of representable regular rings with involution: A counterexample

Christian Herrmann

Bruns and Roddy constructed a $3$ -generated modular ortholattice $L$ which cannot be embedded into any complete modular ortholattice. Motivated by their approach, we use shift oper…

math.LO2024

On the equational theory of finite modular lattices

Christian Herrmann

It is shown that there is $N$ such that there is no algorithm to decide for identities in at most $N$ variables validity in the class of finite modular lattices. This is based on S…