From: lordi Date: Fri, 31 May 2002 16:48:07 +0000 (+0000) Subject: diff and sortedby implemented X-Git-Tag: V_0_3_0_debian_8~64 X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=f870fdd883e3380f77f260709d4cb76e9d5def2b;p=helm.git diff and sortedby implemented --- diff --git a/helm/ocaml/mathql_interpreter/.depend b/helm/ocaml/mathql_interpreter/.depend index 7ee73d95c..71ddf6b00 100644 --- a/helm/ocaml/mathql_interpreter/.depend +++ b/helm/ocaml/mathql_interpreter/.depend @@ -1,3 +1,5 @@ +diff.cmi: mathql_semantics.cmo +sortedby.cmi: mathql_semantics.cmo select.cmi: mathql_semantics.cmo intersect.cmi: mathql_semantics.cmo union.cmi: mathql_semantics.cmo @@ -11,10 +13,10 @@ utility.cmo: dbconn.cmi utility.cmi utility.cmx: dbconn.cmx utility.cmi func.cmo: dbconn.cmi utility.cmi func.cmi func.cmx: dbconn.cmx utility.cmx func.cmi -diff.cmo: diff.cmi -diff.cmx: diff.cmi -sortedby.cmo: func.cmi utility.cmi sortedby.cmi -sortedby.cmx: func.cmx utility.cmx sortedby.cmi +diff.cmo: mathql_semantics.cmo diff.cmi +diff.cmx: mathql_semantics.cmx diff.cmi +sortedby.cmo: func.cmi mathql_semantics.cmo utility.cmi sortedby.cmi +sortedby.cmx: func.cmx mathql_semantics.cmx utility.cmx sortedby.cmi select.cmo: func.cmi mathql_semantics.cmo utility.cmi select.cmi select.cmx: func.cmx mathql_semantics.cmx utility.cmx select.cmi intersect.cmo: mathql_semantics.cmo intersect.cmi diff --git a/helm/ocaml/mathql_interpreter/dbconn.ml b/helm/ocaml/mathql_interpreter/dbconn.ml index e46f89cb2..dd4ae5f02 100644 --- a/helm/ocaml/mathql_interpreter/dbconn.ml +++ b/helm/ocaml/mathql_interpreter/dbconn.ml @@ -20,7 +20,7 @@ * MA 02111-1307, USA. * * For details, see the HELM World-Wide-Web page, - * http://cs.unibo.it/helm/. + * http://www.cs.unibo.it/helm/. *) (* @@ -53,7 +53,7 @@ let conn = ref None;; let pgc () = match !conn with None -> raise (MQInvalidConnection connection_param) - | Some c -> c + | Some c -> c ;; (* diff --git a/helm/ocaml/mathql_interpreter/diff.ml b/helm/ocaml/mathql_interpreter/diff.ml index 41e41c73b..b32468e40 100644 --- a/helm/ocaml/mathql_interpreter/diff.ml +++ b/helm/ocaml/mathql_interpreter/diff.ml @@ -27,91 +27,58 @@ * implementazione del comando DIFF *) -(* - * - *) -let xres_fill_context hr h1 l1 = - match l1 with - [] -> [] - | _ -> - let hh = List.combine h1 l1 - in - List.map - (fun x -> - if (List.mem_assoc x hh) then - List.assoc x hh - else - "" - ) - hr +exception NotCompatible;; + +(* intersect_attributes is successful iff there is no attribute with *) +(* two different values in the two lists. The returned list is the *) +(* union of the two lists. *) +let rec intersect_attributes (attr1, attr2) = + match attr1, attr2 with + [],_ -> attr2 + | _,[] -> attr1 + | (key1,value1)::tl1, (key2,_)::_ when key1 < key2 -> + (key1,value1)::(intersect_attributes (tl1,attr2)) + | (key1,_)::_, (key2,value2)::tl2 when key2 < key1 -> + (key2,value2)::(intersect_attributes (attr1,tl2)) + | entry1::tl1, entry2::tl2 when entry1 = entry2 -> + entry1::(intersect_attributes (tl1,tl2)) + | _, _ -> raise NotCompatible (* same keys, different values *) ;; (* * implementazione del comando DIFF *) -let diff_ex alist1 alist2 = - let head1 = List.hd alist1 - and tail1 = List.tl alist1 - and head2 = List.hd alist2 - and tail2 = List.tl alist2 (* e fin qui ... *) - in - match (head1, head2) with - ([], _) -> assert false (* gli header non devono mai essere vuoti *) - | (_, []) -> assert false (* devono contenere almeno [retVal] *) - | (_, _) -> let headr = (head2 @ - (List.find_all - (function t -> not (List.mem t head2)) - head1) - ) in (* header del risultato finale *) - List.append (* il risultato finale e' la concatenazione ...*) - [headr] (* ... dell'header costruito prima ...*) - (match (tail1, tail2) with (* e di una coda "unione" *) - ([], _) -> tail2 (* va bene perche' l'altra lista e' vuota *) - | (_, []) -> tail1 (* va bene perche' l'altra lista e' vuota *) - | (_, _) -> - let first = (* parte dell'unione che riguarda solo il primo set *) - List.map (fun l -> [List.hd l] @ - xres_fill_context - (List.tl headr) (List.tl head1) (List.tl l) - ) tail1 - in - List.fold_left - (fun par x -> - let y = (* elemento candidato ad entrare *) - [List.hd x] - @ - xres_fill_context - (List.tl headr) (List.tl head2) (List.tl x) - in - par @ if (List.find_all (fun t -> t = y) par) = [] then - [y] - else - [] - ) - first - tail2 -(* first @ - List.map (fun l -> [List.hd l] @ - xres_fill_context - (List.tl headr) (List.tl head2) (List.tl l) - ) tail2 -*) - ) (* match *) +let rec diff_ex l1 l2 = + let module S = Mathql_semantics in + match (l1, l2) with + [],_ -> [] + | l,[] -> l + | {S.uri = uri1}::_, {S.uri = uri2}::tl2 when uri2 < uri1 -> + (diff_ex l1 tl2) + | {S.uri = uri1 ; S.attributes = attributes1}::tl1, + {S.uri = uri2}::_ when uri1 < uri2 -> + {S.uri = uri1 ; S.attributes = attributes1 ; S.extra = ""}::(diff_ex tl1 l2) + | {S.uri = uri1 ; S.attributes = attributes1}::tl1, + {S.uri = uri2 ; S.attributes = attributes2}::tl2 -> + try + let attributes' = intersect_attributes (attributes1, attributes2) in + diff_ex tl1 tl2 + with + NotCompatible -> + {S.uri = uri1 ; S.attributes = attributes1 ; S.extra = ""}::(diff_ex tl1 tl2) ;; -(** TEST **) - -(* -let h1 = ["retVal"; "a"; "b"];; -let l1 = ["pippo"; "3"; "3"];; -let l3 = ["pluto"; "7"; "8"] -let r1 = [h1; l1; l3];; - -(*let h2 = ["retVal"; "b"; "c"];; -let l2 = ["pippo"; "3"; "1"];;*) -let h2 = ["retVal"; "a"; "b"];; -let l2 = ["pippo"; "3"; "3"];; -let r2 = [h2; l2];; +let diff_ex l1 l2 = + let before = Unix.time () in + let res = diff_ex l1 l2 in + let after = Unix.time () in + let ll1 = string_of_int (List.length l1) in + let ll2 = string_of_int (List.length l2) in + let diff = string_of_float (after -. before) in + prerr_endline + ("DIFF(" ^ ll1 ^ ", " ^ ll2 ^ ") = " ^ string_of_int (List.length res) ^ + ": " ^ diff ^ "s") ; + flush stderr ; + res +;; -List.map (fun l -> List.iter print_endline l) (xres_union (r1, r2));; -*) diff --git a/helm/ocaml/mathql_interpreter/diff.mli b/helm/ocaml/mathql_interpreter/diff.mli index d3a57f708..8c247687f 100644 --- a/helm/ocaml/mathql_interpreter/diff.mli +++ b/helm/ocaml/mathql_interpreter/diff.mli @@ -23,4 +23,5 @@ * http://cs.unibo.it/helm/. *) -val diff_ex : string list list -> string list list -> string list list +val diff_ex : + Mathql_semantics.result -> Mathql_semantics.result -> Mathql_semantics.result diff --git a/helm/ocaml/mathql_interpreter/eval.ml b/helm/ocaml/mathql_interpreter/eval.ml index 81be80520..43296cd07 100644 --- a/helm/ocaml/mathql_interpreter/eval.ml +++ b/helm/ocaml/mathql_interpreter/eval.ml @@ -37,7 +37,7 @@ let rec patterneval p = [] -> "" | head::tail -> let h = match head with - MQBC (s) -> Str.global_replace (Str.regexp "\.") "\\\\\." s + MQBC s -> Str.global_replace (Str.regexp "\.") "\\\\\." s | MQBD -> "/" | MQBQ -> "[^/#]?" | MQBS -> "[^/#]*" @@ -46,18 +46,22 @@ let rec patterneval p = h ^ (patterneval tail) ;; +let rec fieval fi = + match fi with + [] -> "" + | MQFC i :: tail -> "/" ^ (string_of_int i) ^ (fieval tail) + | MQFS :: tail -> "[^/]*" ^ (fieval tail) + | MQFSS :: tail -> ".*" ^ (fieval tail) +;; + (* * conversione di un fragment identifier *) let fieval fi = -match fi with - [] -> "" - | MQFC i :: tail -> - let s = "#xpointer\\\\(1/" ^ string_of_int (i) in - match tail with - [] -> s ^ "\\\\)" - | MQFC j :: tail2 -> - s ^ "/" ^ string_of_int j ^ "\\\\)" + if fi = [] then + "" + else + "#xpointer\\\\(1" ^ fieval fi ^ "\\\\)" ;; (* @@ -77,7 +81,8 @@ let exteval ext = *) let preeval p = match p with - Some s -> s + Some s -> s + | None -> "[^/]*" ;; (* @@ -88,6 +93,6 @@ let preeval p = * e con "**". *) let pattern_match (preamble, pattern, fragid) = - " ~ '" ^ (preeval preamble) ^ ":/" ^ (patterneval pattern) ^ (fieval fragid) ^ "'" + " ~ '^" ^ (preeval preamble) ^ ":/" ^ (patterneval pattern) ^ (fieval fragid) ^ "$'" ;; diff --git a/helm/ocaml/mathql_interpreter/intersect.ml b/helm/ocaml/mathql_interpreter/intersect.ml index 6bd620a10..4152a280d 100644 --- a/helm/ocaml/mathql_interpreter/intersect.ml +++ b/helm/ocaml/mathql_interpreter/intersect.ml @@ -55,13 +55,64 @@ let rec intersect_ex l1 l2 = {S.uri = uri2 ; S.attributes = attributes2}::tl2 -> try let attributes' = intersect_attributes (attributes1,attributes2) in - {S.uri = uri1 ; S.attributes = attributes'}::(intersect_ex tl1 tl2) + {S.uri = uri1 ; S.attributes = attributes' ; S.extra = ""}::(intersect_ex tl1 tl2) with NotCompatible -> intersect_ex tl1 tl2 ;; let intersect_ex l1 l2 = + (* PRE-CLAUDIO + (*let _ = print_string ("INTERSECT ") + and t = Unix.time () in*) + let result = + match (l1, l2) with + ((head1::tail1), (head2::tail2)) -> + (match (head1, head2) with + ([], _) -> assert false (* gli header non devono mai essere vuoti *) + | (_, []) -> assert false (* devono contenere almeno [retVal] *) + | (_, _) -> + (match (tail1, tail2) with + ([], _) -> [["retVal"]] (* se una delle due code e' vuota... *) + | (_, []) -> [["retVal"]] (* ... l'intersezione e' vuota *) + | (_, _) -> + [head2 @ + (List.find_all + (function t -> not (List.mem t head2)) + head1 + ) + ] (* header del risultato finale *) + @ + intersect_tails (List.tl head1) tail1 (List.tl head2) tail2 + (* + List.fold_left + (fun par1 elem1 -> par1 @ + List.map + (fun elem2 -> + [(List.hd elem1)] @ + (xres_join_context (List.tl head1) (List.tl elem1) + (List.tl head2) (List.tl elem2) + ) + ) + (List.find_all (* *) + (fun elem2 -> (* trova tutti gli elementi della lista tail2 *) + ((List.hd elem1) = (List.hd elem2)) && (* che stanno in tail1 *) + not ((xres_join_context (List.tl head1) (List.tl elem1) + (List.tl head2) (List.tl elem2)) = []) + (* e per i quali la xres_join_context non sia vuota *) + ) + tail2 (* List.find_all *) + ) + ) + [] + tail1 (* per ogni elemento di tail1 applica la List.fold_left *) + *) + ) (* match *) + ) + | _ -> [] + in + (*let _ = print_endline (string_of_float (Unix.time () -. t)); flush stdout in*) + result*) let before = Unix.time () in let res = intersect_ex l1 l2 in let after = Unix.time () in diff --git a/helm/ocaml/mathql_interpreter/mathql_semantics.ml b/helm/ocaml/mathql_interpreter/mathql_semantics.ml index f618e1e5c..2af88a63c 100644 --- a/helm/ocaml/mathql_interpreter/mathql_semantics.ml +++ b/helm/ocaml/mathql_interpreter/mathql_semantics.ml @@ -20,12 +20,12 @@ * MA 02111-1307, USA. * * For details, see the HELM World-Wide-Web page, - * http://cs.unibo.it/helm/. + * http://www.cs.unibo.it/helm/. *) (* attributes are sorted w.r.t. their name in increasing order *) type attributed_uri = - { uri: string ; attributes : (MathQL.mqsvar * string) list } + { uri: string ; attributes : (MathQL.mqsvar * string) list ; extra : string} type attributed_uri_env = (MathQL.mqrvar * attributed_uri) list diff --git a/helm/ocaml/mathql_interpreter/mqint.ml b/helm/ocaml/mathql_interpreter/mqint.ml index dce67f864..ee56718c5 100644 --- a/helm/ocaml/mathql_interpreter/mqint.ml +++ b/helm/ocaml/mathql_interpreter/mqint.ml @@ -77,12 +77,10 @@ let rec execute_ex env = pattern_ex (apreamble, apattern, afragid) | MQUnion (l1, l2) -> union_ex (execute_ex env l1) (execute_ex env l2) -(* | MQDiff (l1, l2) -> diff_ex (execute_ex env l1) (execute_ex env l2) | MQSortedBy (l, o, f) -> sortedby_ex (execute_ex env l) o f -*) | MQIntersect (l1, l2) -> intersect_ex (execute_ex env l1) (execute_ex env l2) | MQRVarOccur rvar -> [List.assoc rvar env] @@ -128,10 +126,11 @@ let xres_to_res l = MQRefs (List.map (function l -> - match Str.split (Str.regexp ":\|#\|/") l with - hd::tl -> ( + (*let _ = print_endline ("DEBUG: (mqint.ml: xres_to_res)" ^ l) in*) + match Str.split (Str.regexp ":\|#\|/\|(\|)") l with + hd::""::tl -> ( match List.rev tl with - ")"::n::"xpointer(1"::tail -> + n::"1"::"xpointer"::tail -> ( Some hd, List.fold_left @@ -144,7 +143,7 @@ let xres_to_res l = tail, [MQFC (int_of_string n)] ) - | ")"::n::m::"xpointer(1"::tail -> + | n::m::"1"::"xpointer"::tail -> ( Some hd, List.fold_left @@ -171,7 +170,7 @@ let xres_to_res l = [] ) ) - | [] -> assert false + | _ -> assert false ) tmp ) diff --git a/helm/ocaml/mathql_interpreter/pattern.ml b/helm/ocaml/mathql_interpreter/pattern.ml index 7aa09f172..39c9f3c3f 100644 --- a/helm/ocaml/mathql_interpreter/pattern.ml +++ b/helm/ocaml/mathql_interpreter/pattern.ml @@ -20,7 +20,7 @@ * MA 02111-1307, USA. * * For details, see the HELM World-Wide-Web page, - * http://cs.unibo.it/helm/. + * http://www.cs.unibo.it/helm/. *) (* @@ -34,14 +34,26 @@ open Mathql_semantics;; let pattern_ex (apreamble, apattern, afragid) = let c = pgc () in + (*let _ = print_string ("USE ") + and t = Unix.time () in*) (*let r1 = helm_class_id "MathResource" in*) (*let qq = "select att0 from t" ^ r1 ^ " where att0 " ^ (pattern_match apreamble apattern afragid) ^ " order by t" ^ r1 ^ ".att0 asc" in*) + (*PRE-CLAUDIO + let qq = "select uri from registry where uri " ^ (pattern_match apreamble apattern afragid) ^ " order by registry.uri asc" in + let result = + let res = + c#exec (qq) + in + [["retVal"]] @ List.map (fun l -> [l]) (pgresult_to_string_list res)*) let qq = "select uri from registry where uri " ^ (pattern_match (apreamble, apattern, afragid)) ^ " order by registry.uri asc" in (*let _ = print_endline qq in*) let res = c#exec (qq) in +(* PRE-CLAUDIO + (*let _ = print_endline (string_of_float (Unix.time () -. t)); flush stdout in*) + result*) List.map - (function uri -> {uri = uri ; attributes = []}) + (function uri -> {uri = uri ; attributes = [] ; extra = ""}) (pgresult_to_string_list res) ;; diff --git a/helm/ocaml/mathql_interpreter/sortedby.ml b/helm/ocaml/mathql_interpreter/sortedby.ml index db2258d56..d468ae2fc 100644 --- a/helm/ocaml/mathql_interpreter/sortedby.ml +++ b/helm/ocaml/mathql_interpreter/sortedby.ml @@ -20,7 +20,7 @@ * MA 02111-1307, USA. * * For details, see the HELM World-Wide-Web page, - * http://cs.unibo.it/helm/. + * http://www.cs.unibo.it/helm/. *) (* @@ -35,20 +35,28 @@ open Utility;; * implementazione del comando SORTEDBY *) let sortedby_ex alist order afunc = - [List.hd alist] - @ - List.map - (List.tl) - (Sort.list - (fun a b -> - match order with - MQAsc -> (List.hd a) < (List.hd b) - | MQDesc -> (List.hd a) > (List.hd b) - ) - (List.map - (fun l -> [apply_func afunc (List.hd l)] @ l) - (List.tl alist) - ) - ) + let before = Unix.time () in + let res = + let module S = Mathql_semantics in + (Sort.list + (fun {S.extra = e1} {S.extra = e2} -> + match order with + MQAsc -> e1 < e2 + | MQDesc -> e1 > e2 + ) + (List.map + (fun {S.uri = u ; S.attributes = attr} -> {S.uri = u ; S.attributes = attr ; S.extra = (apply_func afunc u)}) + alist + ) + ) + in + let after = Unix.time () + and ll1 = string_of_int (List.length alist) in + let diff = string_of_float (after -. before) in + prerr_endline + ("SORTEDBY(" ^ ll1 ^ ") = " ^ string_of_int (List.length res) ^ + ": " ^ diff ^ "s") ; + flush stderr ; + res ;; diff --git a/helm/ocaml/mathql_interpreter/sortedby.mli b/helm/ocaml/mathql_interpreter/sortedby.mli index 6c01aa0e6..863581a09 100644 --- a/helm/ocaml/mathql_interpreter/sortedby.mli +++ b/helm/ocaml/mathql_interpreter/sortedby.mli @@ -24,4 +24,4 @@ *) val sortedby_ex : - string list list -> MathQL.mqorder -> MathQL.mqfunc -> string list list + Mathql_semantics.result -> MathQL.mqorder -> MathQL.mqfunc -> Mathql_semantics.result diff --git a/helm/ocaml/mathql_interpreter/union.ml b/helm/ocaml/mathql_interpreter/union.ml index 65f73503b..2e83b7a7d 100644 --- a/helm/ocaml/mathql_interpreter/union.ml +++ b/helm/ocaml/mathql_interpreter/union.ml @@ -114,13 +114,16 @@ let rec union_ex l1 l2 = [],l | l,[] -> l | ({S.uri = uri1} as entry1)::tl1, - ({S.uri = uri2} as entry2)::_ when uri1 < uri2 || entry1 < entry2 -> + ({S.uri = uri2} as entry2)::_ when uri1 < uri2 -> entry1::(union_ex tl1 l2) | ({S.uri = uri1} as entry1)::_, - ({S.uri = uri2} as entry2)::tl2 when uri2 < uri1 || entry2 < entry1 -> + ({S.uri = uri2} as entry2)::tl2 when uri2 < uri1 -> entry2::(union_ex l1 tl2) | entry1::tl1,entry2::tl2 -> (* same entry *) - entry1::(union_ex tl1 tl2) + if entry1 = entry2 then (* same attributes *) + entry1::(union_ex tl1 tl2) + else + assert false ;; let union_ex l1 l2 = diff --git a/helm/ocaml/mathql_interpreter/use.ml b/helm/ocaml/mathql_interpreter/use.ml index ecc12f01d..ed8a855ec 100644 --- a/helm/ocaml/mathql_interpreter/use.ml +++ b/helm/ocaml/mathql_interpreter/use.ml @@ -20,7 +20,7 @@ * MA 02111-1307, USA. * * For details, see the HELM World-Wide-Web page, - * http://cs.unibo.it/helm/. + * http://www.cs.unibo.it/helm/. *) (* @@ -45,6 +45,44 @@ open Dbconn;; * comando USE/USED BY *) let use_ex alist asvar usek = + (*(*let _ = print_string ("USE ") + and t = Unix.time () in*) + let result = + let c = pgc () + in + [ (List.hd alist) @ [asvar] ] + @ + Sort.list + (fun l m -> List.hd l < List.hd m) + (List.fold_left + (fun parziale xres -> + (*let r1 = helm_property_id usek + and r2 = helm_property_id "position" + and r3 = helm_property_id "occurrence" + in + let qq = "select distinct t" ^ r3 ^ ".att1, t" ^ r2 ^ ".att1 " ^ + "from t" ^ r3 ^ ", t" ^ r2 ^ ", t" ^ r1 ^ " " ^ + "where " ^ "t" ^ r1 ^ ".att0 = '" ^ (List.hd xres) ^ "' and t" ^ r1 ^ + ".att1 = t" ^ r2 ^ ".att0 and t" ^ r1 ^ ".att1 = t" ^ r3 ^ + ".att0 order by t" ^ r3 ^ ".att1 asc"*) + let tv = pgresult_to_string (c#exec ("select id from registry where uri='" ^ (List.hd xres) ^ "'")) in + let _ = print_endline ("DEBUG (use.ml): " ^ tv) in + let qq = "select uri, context from t" ^ tv ^ " where back_for='" ^ usek ^ "'" in + let res = c#exec qq in + (List.map + (fun l -> [List.hd l] @ List.tl xres @ List.tl l) + res#get_list + ) + @ + parziale + ) + [] + (List.tl alist) + ) + in + (*let _ = print_endline (string_of_float (Unix.time () -. t)); flush stdout in*) + + *) let module S = Mathql_semantics in let _ = print_string ("USE ") and t = Unix.time () in @@ -55,7 +93,8 @@ let result = (List.fold_left (fun parziale {S.uri = uri ; S.attributes = attributes} -> print_string uri ; - (*let r1 = helm_property_id usek + (* RSSDB + let r1 = helm_property_id usek and r2 = helm_property_id "position" and r3 = helm_property_id "occurrence" in @@ -63,7 +102,8 @@ let result = "from t" ^ r3 ^ ", t" ^ r2 ^ ", t" ^ r1 ^ " " ^ "where " ^ "t" ^ r1 ^ ".att0 = '" ^ (List.hd xres) ^ "' and t" ^ r1 ^ ".att1 = t" ^ r2 ^ ".att0 and t" ^ r1 ^ ".att1 = t" ^ r3 ^ - ".att0 order by t" ^ r3 ^ ".att1 asc"*) + ".att0 order by t" ^ r3 ^ ".att1 asc" + *) let tv = pgresult_to_string (c#exec ("select id from registry where uri='" ^ uri ^ "'")) @@ -75,7 +115,7 @@ let result = let res = c#exec qq in (List.map (function - [uri;context] -> {S.uri = uri ; S.attributes = [asvar, context]} + [uri;context] -> {S.uri = uri ; S.attributes = [asvar, context] ; S.extra = ""} | _ -> assert false ) res#get_list ) @ diff --git a/helm/ocaml/mathql_interpreter/utility.ml b/helm/ocaml/mathql_interpreter/utility.ml index e3776cfbd..5ea9b7e67 100644 --- a/helm/ocaml/mathql_interpreter/utility.ml +++ b/helm/ocaml/mathql_interpreter/utility.ml @@ -20,7 +20,7 @@ * MA 02111-1307, USA. * * For details, see the HELM World-Wide-Web page, - * http://cs.unibo.it/helm/. + * http://www.cs.unibo.it/helm/. *) (*