let bind_formals called_kf vs =
let rec bind xvars xs vs =
match xs , vs with
| x::xs , v::vs -> bind (Varinfo.Map.add x v xvars) xs vs
| _ -> xvars
in (* prototypes have exactly the good number of variables *)
bind Varinfo.Map.empty (Kernel_function.get_formals called_kf) vs