let prop_txt p = match p with
| PKfctPre _ -> "pre"
| PKspecPre (s, _idp) -> Pretty_utils.sfprintf "before_sid_%d" s.sid
| PKfctPost _ -> "post"
| PKspecPost (s, _idp) -> Pretty_utils.sfprintf "after_sid_%d" s.sid
| PKloopInv (s, ca_id, _p) -> Pretty_utils.sfprintf "%d_loop_%d_inv" ca_id s.sid
| PKassert (ca_id, before_after, s, _a) ->
Pretty_utils.sfprintf "%d_%s_sid_%d" ca_id
(if before_after then "before" else "after") s.sid
| PKbhvProp (txt, _) -> txt