Definition nfelim x a b c d e :=
felim x a b c d e nil.

(* Specifications: *)
Lemma  nfelim_c x a b c d e :
{v[x]} = {k[a]} .* {v[b]} + {k[c]} .* {v[d]} :> vect K ->
{e[nfelim x a b c d e]} = {e[e]}.