let metasenv = List.filter (fun j,_ -> j <> metano) metasenv in
let subst = (metano, (attrs, ctx, bo_, ty)) :: subst in
let status = status#set_obj (n,h,metasenv,subst,o) in
let metasenv = List.filter (fun j,_ -> j <> metano) metasenv in
let subst = (metano, (attrs, ctx, bo_, ty)) :: subst in
let status = status#set_obj (n,h,metasenv,subst,o) in