dot / cross .... anticommutator / commutator .... cayley-dickson ... anti-involution ... "anti-scalar product" .... ??? ....

heisenberg ... "mystical 2n+1 stuff" ... cayley-dickson .... ?? contact structure ??? ....

?? sub-[projective lightcone] in general ... split quaternion subalg in split octonions in particular .... ??? .....

?? with / without tweak, standard rolling trajectory as special case of null subspace / partial isometry graph .... ???? .... ?? split quaternion algebra as _not_ such .... ??? .... some confusion ?? ... ?? "lightcone subcone" vs nil / null such ... ??? ....

?? distribution vs its collection of "geodesic rolling trajectories" .... ??? .... ?? as basically equivalent, and latter as more convenient / better for certain purposes ... ??? ..... ?? ask huerta about this ?? ... ?? to what extent we tried this approach before .... ??? ...

?? "diaconescu's and giraud's thms together" ... ???? .... presheaves on small category .... ?? .... ??? canonical grothendieck topology ... ?? "covering of non-flat / non-representable thing by canonical presentation ..." ??? .... ???? ..... ???? .....

?? coherence confusion ??? ....