The coincidence site lattice (CSL) problem and its generalization to Z-modules in Euclidean 3-space is revisited, and various results and conjectures are proved in a unified way, ...
For sums of radicals Pk i=1 i di p i, where i; i are elements of some real algebraic number eld Q( ); di p i 2 R; we present a deterministic polynomial time algorithm to decide wh...