(*========================================================== ============================================================ TOPOLOGICAL FMAPS, HMAPS -  WITH TAGS AND EMBEDDINGS  PART 5:  characteristics, eqc, expf / L0, L_B  COMPLETE FOR DIM 0 (DIM 1 IN THE NEXT FILE): OK! ============================================================ ==========================================================*)
Require Export Jordan4.

Lemma nv_B:forall (m:fmap)(k:dim)(x:dart),
inv_hmap m -> succ m k x ->
nv (B m k x) = nv m +
if (eq_dim_dec k one) then 1 else 0.