We study relations on trees defined by first-order constraints over a vocabulary that includes the tree extension relation Ì Ì ¼, holding if and only if every branch of Ì ex...
We show that the locally free class group of an order in a semisimple algebra over a number field is isomorphic to a certain ray class group. This description is then used to prese...
Experts often disagree about the organization of biological taxa. The shifting definitions of taxonomic names complicate otherwise simple queries concerning these taxa. For examp...
We describe the new software package Aligator for automatically inferring polynomial loop invariants. The package combines algorithms from symbolic summation and polynomial algebra...
: Since all the algebras connected to logic have, more or less explicitely, an associated order relation, it follows that they have two presentations, dual to each other. We classi...