Finite_table:

Modify def castTc.
Add and prove castT{r,c,}_comp, castT_comp_{r,c}{l,r}.

geometry:
Rename convex_envelop_cast -> convex_envelop_castF_incl (proof simplified).
Add and prove convex_envelop_castF.

FE:
Add and prove nos_eq.
Modify FE_ext (use castT).

FE_simplex:
Remove useless defs ord_nvtx_Sd, ord_nvtx_Sd.
Modify def vtx_ref, FE_cur.
Simplify proofs of K_geom_{ref,cur}_def_correct.

FE_LagP:
Simplify proof of FE_cur_eq (use castT and its properties).