??visualizing (or something... and so forth...) tangent space at point of apartment variety as rep of cartan... specific examples... b2... and so forth... ??sa "tame vs non-tame orientations" or something... and so forth or something...

??left-universal property of algebroid of reps of given quiver, wrt various doctrines... involving or omitting tensor product, kernels, cokernels ... and so forth... ??more generally, general case of abelian gp-valued or vector space-valued pre-sheaves (??or sheaves wrt a grothendieck topology?? ... and so forth... or something...) on a cat... ??"generalizations / analogs of "diaconescu's theorem"...