let num_of_bhv_from bhv (out, _) =
match bhv.b_assigns with
WritesAny -> Wp_parameters.fatal "no \\from in this behavior ???"
| Writes l ->
let add n (o, f) = match f with FromAny -> n
| From _ ->
if Logic_utils.is_same_identified_term out o then
raise (Found n)
else n+1
in
try
let _ = List.fold_left add 1 l in
Wp_parameters.fatal "didn't found this \\from"
with Found n -> n