module Orderings (B : Terms.Blob) = struct
+ module Pp = Pp.Pp(B)
+
type weight = int * (int * int) list;;
let string_of_weight (cw, mw) =
| Terms.Equation (l,r,_,_) ->
let wl, ml = weight_of_term l in
let wr, mr = weight_of_term r in
- let wl = weight_of_polynomial wl ml in
- let wr = weight_of_polynomial wr mr in
- - (abs (wl-wr))
+ let wl = weight_of_polynomial wl ml in
+ let wr = weight_of_polynomial wr mr in
+ - (abs (wl-wr))
;;
(* Riazanov: 3.1.5 pag 38 *)
let compare_weights (h1, w1) (h2, w2) =
let rec aux hdiff (lt, gt) diffs w1 w2 =
match w1, w2 with
- | ((var1, w1)::tl1) as l1, (((var2, w2)::tl2) as l2) ->
- if var1 = var2 then
- let diffs = (w1 - w2) + diffs in
- let r = compare w1 w2 in
- let lt = lt or (r < 0) in
- let gt = gt or (r > 0) in
- if lt && gt then XINCOMPARABLE else
- aux hdiff (lt, gt) diffs tl1 tl2
- else if var1 < var2 then
- if lt then XINCOMPARABLE else
- aux hdiff (false,true) (diffs+w1) tl1 l2
- else
- if gt then XINCOMPARABLE else
- aux hdiff (true,false) (diffs-w2) l1 tl2
- | [], (_,w2)::tl2 ->
- if gt then XINCOMPARABLE else
- aux hdiff (true,false) (diffs-w2) [] tl2
- | (_,w1)::tl1, [] ->
- if lt then XINCOMPARABLE else
- aux hdiff (false,true) (diffs+w1) tl1 []
- | [], [] ->
- if lt then
- if hdiff <= 0 then XLT
+ | ((var1, w1)::tl1) as l1, (((var2, w2)::tl2) as l2) ->
+ if var1 = var2 then
+ let diffs = (w1 - w2) + diffs in
+ let r = compare w1 w2 in
+ let lt = lt or (r < 0) in
+ let gt = gt or (r > 0) in
+ if lt && gt then XINCOMPARABLE else
+ aux hdiff (lt, gt) diffs tl1 tl2
+ else if var1 < var2 then
+ if lt then XINCOMPARABLE else
+ aux hdiff (false,true) (diffs+w1) tl1 l2
+ else
+ if gt then XINCOMPARABLE else
+ aux hdiff (true,false) (diffs-w2) l1 tl2
+ | [], (_,w2)::tl2 ->
+ if gt then XINCOMPARABLE else
+ aux hdiff (true,false) (diffs-w2) [] tl2
+ | (_,w1)::tl1, [] ->
+ if lt then XINCOMPARABLE else
+ aux hdiff (false,true) (diffs+w1) tl1 []
+ | [], [] ->
+ if lt then
+ if hdiff <= 0 then XLT
else if (- diffs) >= hdiff then XLE else XINCOMPARABLE
- else if gt then
- if hdiff >= 0 then XGT
+ else if gt then
+ if hdiff >= 0 then XGT
else if diffs >= (- hdiff) then XGE else XINCOMPARABLE
- else
- if hdiff < 0 then XLT
- else if hdiff > 0 then XGT
+ else
+ if hdiff < 0 then XLT
+ else if hdiff > 0 then XGT
else XEQ
in
aux (h1-h2) (false,false) 0 w1 w2
* If we give back XEQ, no inference rule *
* will be applied on this equality *)
| Terms.Var i, Terms.Var j when i = j ->
- XEQ
+ XEQ
(* 1. *)
| Terms.Var _, _
| _, Terms.Var _ -> XINCOMPARABLE
) else r
| res -> res
;;
+
+ let rec lpo s t =
+ match s,t with
+ | s, t when s = t ->
+ XEQ
+ | Terms.Var _, Terms.Var _ ->
+ XINCOMPARABLE
+ | _, Terms.Var i ->
+ if (List.mem i (Terms.vars_of_term s)) then XGT
+ else XINCOMPARABLE
+ | Terms.Var i,_ ->
+ if (List.mem i (Terms.vars_of_term t)) then XLT
+ else XINCOMPARABLE
+ | Terms.Node (hd1::tl1), Terms.Node (hd2::tl2) ->
+ let rec ge_subterm t ol = function
+ | [] -> (false, ol)
+ | x::tl ->
+ let res = lpo x t in
+ match res with
+ | XGT | XEQ -> (true,res::ol)
+ | o -> ge_subterm t (o::ol) tl
+ in
+ let (res, l_ol) = ge_subterm t [] tl1 in
+ if res then XGT
+ else let (res, r_ol) = ge_subterm s [] tl2 in
+ if res then XLT
+ else begin
+ let rec check_subterms t = function
+ | _,[] -> true
+ | o::ol,_::tl ->
+ if o = XLT then check_subterms t (ol,tl)
+ else false
+ | [], x::tl ->
+ if lpo x t = XLT then check_subterms t ([],tl)
+ else false
+ in
+ match aux_ordering hd1 hd2 with
+ | XGT -> if check_subterms s (r_ol,tl2) then XGT
+ else XINCOMPARABLE
+ | XLT -> if check_subterms t (l_ol,tl1) then XLT
+ else XINCOMPARABLE
+ | XEQ ->
+ let lex = List.fold_left2
+ (fun acc si ti -> if acc = XEQ then lpo si ti else acc)
+ XEQ tl1 tl2
+ in
+ (match lex with
+ | XGT ->
+ if List.for_all (fun x -> lpo s x = XGT) tl2 then XGT
+ else XINCOMPARABLE
+ | XLT ->
+ if List.for_all (fun x -> lpo x t = XLT) tl1 then XLT
+ else XINCOMPARABLE
+ | o -> o)
+ | XINCOMPARABLE -> XINCOMPARABLE
+ | _ -> assert false
+ end
+ | _,_ -> aux_ordering s t
+ ;;
+
+let rec lpo_old t1 t2 =
+ match t1, t2 with
+ | t1, t2 when t1 = t2 -> XEQ
+ | t1, (Terms.Var m) ->
+ if List.mem m (Terms.vars_of_term t1) then XGT else XINCOMPARABLE
+ | (Terms.Var m), t2 ->
+ if List.mem m (Terms.vars_of_term t2) then XLT else XINCOMPARABLE
+ | Terms.Node (hd1::tl1), Terms.Node (hd2::tl2) -> (
+ let res =
+ let f o r t =
+ if r then true else
+ match lpo_old t o with
+ | XGT | XEQ -> true
+ | _ -> false
+ in
+ let res1 = List.fold_left (f t2) false tl1 in
+ if res1 then XGT
+ else let res2 = List.fold_left (f t1) false tl2 in
+ if res2 then XLT
+ else XINCOMPARABLE
+ in
+ if res <> XINCOMPARABLE then
+ res
+ else
+ let f o r t =
+ if not r then false else
+ match lpo_old o t with
+ | XGT -> true
+ | _ -> false
+ in
+ match aux_ordering hd1 hd2 with
+ | XGT ->
+ let res = List.fold_left (f t1) true tl2 in
+ if res then XGT
+ else XINCOMPARABLE
+ | XLT ->
+ let res = List.fold_left (f t2) true tl1 in
+ if res then XLT
+ else XINCOMPARABLE
+ | XEQ -> (
+ let lex_res =
+ try
+ List.fold_left2
+ (fun r t1 t2 -> if r <> XEQ then r else lpo_old t1 t2)
+ XEQ tl1 tl2
+ with Invalid_argument _ ->
+ XINCOMPARABLE
+ in
+ match lex_res with
+ | XGT ->
+ if List.fold_left (f t1) true tl2 then XGT
+ else XINCOMPARABLE
+ | XLT ->
+ if List.fold_left (f t2) true tl1 then XLT
+ else XINCOMPARABLE
+ | _ -> XINCOMPARABLE
+ )
+ | _ -> XINCOMPARABLE
+ )
+ | t1, t2 -> aux_ordering t1 t2
+;;
+
let compare_terms x y =
- match nonrec_kbo x y with
- | XINCOMPARABLE -> Terms.Incomparable
- | XGT -> Terms.Gt
- | XLT -> Terms.Lt
- | XEQ -> Terms.Eq
- | _ -> assert false
+ match nonrec_kbo x y with
+(* match lpo x y with *)
+ | XINCOMPARABLE -> Terms.Incomparable
+ | XGT -> Terms.Gt
+ | XLT -> Terms.Lt
+ | XEQ -> Terms.Eq
+ | _ -> assert false
;;
end
projects / helm.git / blobdiff