Codistances of 3-spherical buildings
Let \(\mathcal B\) be a building such that each rank 2 residue is connected far away from a chamber, and each rank 3 residue is spherical and simply 2-connected far away from a chamber; these assumptions hold if the diagram of the building \(\mathcal B\) is simply laced and each panel contains at least 4 chambers. If \(\mathcal B\) admits a codistance (i.e.\ a twinning with a single chamber), then \(\mathcal B\) admits a twinning, which means that \(\mathcal B\) is one half of a twin building.
scientific article; zbMATH DE number 6084003