My 4-D dekanies incorrect

George gave me the following correction to my arguments:

But I think your coordinates are slightly incorrect. It's ingenious to set
up
your coordinates so that the regular octahedron of edge 2sqrt(2) lies in the

w=0 realm and the regular tetrahedron of edge 2sqrt(2) that's opposite the
octahedron lies in the w=1 realm. However, your tetrahedron is too close to
your octahedron! The edge of your dispentachoron is 2sqrt(2), but the
distance from the vertex (2,0,0,0) to the vertex (1, -1,1,1) is only 2,
which
is shorter than the edge and is definitely not allowed in a >convex uniform<

polytope.

I'll have to fix my movies!