match NCicReduction.whd ~subst context ty with
| C.Meta (_,(0,(C.Irl 0 | C.Ctx []))) as ty ->
metasenv, subst, t, ty
- | C.Meta (i,(_,(C.Irl 0 | C.Ctx []))) ->
- metasenv, subst, t, C.Meta(i,(0,C.Irl 0))
+ | C.Meta (i,(_,(C.Irl 0 | C.Ctx []))) -> assert false (*CSC: ???
+ metasenv, subst, t, C.Meta(i,(0,C.Irl 0)) *)
| C.Meta (i,(_,lc)) ->
let len = match lc with C.Irl len->len | C.Ctx l->List.length l in
let metasenv, subst, newmeta =