(* newmeta is the lowest index of the new metas introduced *)
let (consthead,newmetas,arguments,_) =
new_metasenv_for_apply newmeta' proof context termty
(* newmeta is the lowest index of the new metas introduced *)
let (consthead,newmetas,arguments,_) =
new_metasenv_for_apply newmeta' proof context termty