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|
(************************************************************************)
(* v * The Coq Proof Assistant / The Coq Development Team *)
(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012 *)
(* \VV/ **************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(************************************************************************)
open Term
open Util
open Goptions
type s_info=
{mutable created_steps : int; (* node count*)
mutable pruned_steps : int;
mutable created_branches : int; (* path count *)
mutable pruned_branches : int;
mutable created_hyps : int; (* hyps count *)
mutable pruned_hyps : int;
mutable branch_failures : int;
mutable branch_successes : int;
mutable nd_branching : int}
let s_info=
{created_steps = 0; (* node count*)
pruned_steps = 0;
created_branches = 0; (* path count *)
pruned_branches = 0;
created_hyps = 0; (* hyps count *)
pruned_hyps = 0;
branch_failures = 0;
branch_successes = 0;
nd_branching = 0}
let reset_info () =
s_info.created_steps <- 0; (* node count*)
s_info.pruned_steps <- 0;
s_info.created_branches <- 0; (* path count *)
s_info.pruned_branches <- 0;
s_info.created_hyps <- 0; (* hyps count *)
s_info.pruned_hyps <- 0;
s_info.branch_failures <- 0;
s_info.branch_successes <- 0;
s_info.nd_branching <- 0
let pruning = ref true
let opt_pruning=
{optsync=true;
optdepr=false;
optname="Rtauto Pruning";
optkey=["Rtauto";"Pruning"];
optread=(fun () -> !pruning);
optwrite=(fun b -> pruning:=b)}
let _ = declare_bool_option opt_pruning
type form=
Atom of int
| Arrow of form * form
| Bot
| Conjunct of form * form
| Disjunct of form * form
type tag=int
let decomp_form=function
Atom i -> Some (i,[])
| Arrow (f1,f2) -> Some (-1,[f1;f2])
| Bot -> Some (-2,[])
| Conjunct (f1,f2) -> Some (-3,[f1;f2])
| Disjunct (f1,f2) -> Some (-4,[f1;f2])
module Fmap=Map.Make(struct type t=form let compare=compare end)
type sequent =
{rev_hyps: form Intmap.t;
norev_hyps: form Intmap.t;
size:int;
left:int Fmap.t;
right:(int*form) list Fmap.t;
cnx:(int*int*form*form) list;
abs:int option;
gl:form}
let add_one_arrow i f1 f2 m=
try Fmap.add f1 ((i,f2)::(Fmap.find f1 m)) m with
Not_found ->
Fmap.add f1 [i,f2] m
type proof =
Ax of int
| I_Arrow of proof
| E_Arrow of int*int*proof
| D_Arrow of int*proof*proof
| E_False of int
| I_And of proof*proof
| E_And of int*proof
| D_And of int*proof
| I_Or_l of proof
| I_Or_r of proof
| E_Or of int*proof*proof
| D_Or of int*proof
| Pop of int*proof
type rule =
SAx of int
| SI_Arrow
| SE_Arrow of int*int
| SD_Arrow of int
| SE_False of int
| SI_And
| SE_And of int
| SD_And of int
| SI_Or_l
| SI_Or_r
| SE_Or of int
| SD_Or of int
let add_step s sub =
match s,sub with
SAx i,[] -> Ax i
| SI_Arrow,[p] -> I_Arrow p
| SE_Arrow(i,j),[p] -> E_Arrow (i,j,p)
| SD_Arrow i,[p1;p2] -> D_Arrow (i,p1,p2)
| SE_False i,[] -> E_False i
| SI_And,[p1;p2] -> I_And(p1,p2)
| SE_And i,[p] -> E_And(i,p)
| SD_And i,[p] -> D_And(i,p)
| SI_Or_l,[p] -> I_Or_l p
| SI_Or_r,[p] -> I_Or_r p
| SE_Or i,[p1;p2] -> E_Or(i,p1,p2)
| SD_Or i,[p] -> D_Or(i,p)
| _,_ -> anomaly "add_step: wrong arity"
type 'a with_deps =
{dep_it:'a;
dep_goal:bool;
dep_hyps:Intset.t}
type slice=
{proofs_done:proof list;
proofs_todo:sequent with_deps list;
step:rule;
needs_goal:bool;
needs_hyps:Intset.t;
changes_goal:bool;
creates_hyps:Intset.t}
type state =
Complete of proof
| Incomplete of sequent * slice list
let project = function
Complete prf -> prf
| Incomplete (_,_) -> anomaly "not a successful state"
let pop n prf =
let nprf=
match prf.dep_it with
Pop (i,p) -> Pop (i+n,p)
| p -> Pop(n,p) in
{prf with dep_it = nprf}
let rec fill stack proof =
match stack with
[] -> Complete proof.dep_it
| slice::super ->
if
!pruning &&
slice.proofs_done=[] &&
not (slice.changes_goal && proof.dep_goal) &&
not (Intset.exists
(fun i -> Intset.mem i proof.dep_hyps)
slice.creates_hyps)
then
begin
s_info.pruned_steps<-s_info.pruned_steps+1;
s_info.pruned_branches<- s_info.pruned_branches +
List.length slice.proofs_todo;
let created_here=Intset.cardinal slice.creates_hyps in
s_info.pruned_hyps<-s_info.pruned_hyps+
List.fold_left
(fun sum dseq -> sum + Intset.cardinal dseq.dep_hyps)
created_here slice.proofs_todo;
fill super (pop (Intset.cardinal slice.creates_hyps) proof)
end
else
let dep_hyps=
Intset.union slice.needs_hyps
(Intset.diff proof.dep_hyps slice.creates_hyps) in
let dep_goal=
slice.needs_goal ||
((not slice.changes_goal) && proof.dep_goal) in
let proofs_done=
proof.dep_it::slice.proofs_done in
match slice.proofs_todo with
[] ->
fill super {dep_it =
add_step slice.step (List.rev proofs_done);
dep_goal = dep_goal;
dep_hyps = dep_hyps}
| current::next ->
let nslice=
{proofs_done=proofs_done;
proofs_todo=next;
step=slice.step;
needs_goal=dep_goal;
needs_hyps=dep_hyps;
changes_goal=current.dep_goal;
creates_hyps=current.dep_hyps} in
Incomplete (current.dep_it,nslice::super)
let append stack (step,subgoals) =
s_info.created_steps<-s_info.created_steps+1;
match subgoals with
[] ->
s_info.branch_successes<-s_info.branch_successes+1;
fill stack {dep_it=add_step step.dep_it [];
dep_goal=step.dep_goal;
dep_hyps=step.dep_hyps}
| hd :: next ->
s_info.created_branches<-
s_info.created_branches+List.length next;
let slice=
{proofs_done=[];
proofs_todo=next;
step=step.dep_it;
needs_goal=step.dep_goal;
needs_hyps=step.dep_hyps;
changes_goal=hd.dep_goal;
creates_hyps=hd.dep_hyps} in
Incomplete(hd.dep_it,slice::stack)
let embed seq=
{dep_it=seq;
dep_goal=false;
dep_hyps=Intset.empty}
let change_goal seq gl=
{seq with
dep_it={seq.dep_it with gl=gl};
dep_goal=true}
let add_hyp seqwd f=
s_info.created_hyps<-s_info.created_hyps+1;
let seq=seqwd.dep_it in
let num = seq.size+1 in
let left = Fmap.add f num seq.left in
let cnx,right=
try
let l=Fmap.find f seq.right in
List.fold_right (fun (i,f0) l0 -> (num,i,f,f0)::l0) l seq.cnx,
Fmap.remove f seq.right
with Not_found -> seq.cnx,seq.right in
let nseq=
match f with
Bot ->
{seq with
left=left;
right=right;
size=num;
abs=Some num;
cnx=cnx}
| Atom _ ->
{seq with
size=num;
left=left;
right=right;
cnx=cnx}
| Conjunct (_,_) | Disjunct (_,_) ->
{seq with
rev_hyps=Intmap.add num f seq.rev_hyps;
size=num;
left=left;
right=right;
cnx=cnx}
| Arrow (f1,f2) ->
let ncnx,nright=
try
let i = Fmap.find f1 seq.left in
(i,num,f1,f2)::cnx,right
with Not_found ->
cnx,(add_one_arrow num f1 f2 right) in
match f1 with
Conjunct (_,_) | Disjunct (_,_) ->
{seq with
rev_hyps=Intmap.add num f seq.rev_hyps;
size=num;
left=left;
right=nright;
cnx=ncnx}
| Arrow(_,_) ->
{seq with
norev_hyps=Intmap.add num f seq.norev_hyps;
size=num;
left=left;
right=nright;
cnx=ncnx}
| _ ->
{seq with
size=num;
left=left;
right=nright;
cnx=ncnx} in
{seqwd with
dep_it=nseq;
dep_hyps=Intset.add num seqwd.dep_hyps}
exception Here_is of (int*form)
let choose m=
try
Intmap.iter (fun i f -> raise (Here_is (i,f))) m;
raise Not_found
with
Here_is (i,f) -> (i,f)
let search_or seq=
match seq.gl with
Disjunct (f1,f2) ->
[{dep_it = SI_Or_l;
dep_goal = true;
dep_hyps = Intset.empty},
[change_goal (embed seq) f1];
{dep_it = SI_Or_r;
dep_goal = true;
dep_hyps = Intset.empty},
[change_goal (embed seq) f2]]
| _ -> []
let search_norev seq=
let goals=ref (search_or seq) in
let add_one i f=
match f with
Arrow (Arrow (f1,f2),f3) ->
let nseq =
{seq with norev_hyps=Intmap.remove i seq.norev_hyps} in
goals:=
({dep_it=SD_Arrow(i);
dep_goal=false;
dep_hyps=Intset.singleton i},
[add_hyp
(add_hyp
(change_goal (embed nseq) f2)
(Arrow(f2,f3)))
f1;
add_hyp (embed nseq) f3]):: !goals
| _ -> anomaly "search_no_rev: can't happen" in
Intmap.iter add_one seq.norev_hyps;
List.rev !goals
let search_in_rev_hyps seq=
try
let i,f=choose seq.rev_hyps in
let make_step step=
{dep_it=step;
dep_goal=false;
dep_hyps=Intset.singleton i} in
let nseq={seq with rev_hyps=Intmap.remove i seq.rev_hyps} in
match f with
Conjunct (f1,f2) ->
[make_step (SE_And(i)),
[add_hyp (add_hyp (embed nseq) f1) f2]]
| Disjunct (f1,f2) ->
[make_step (SE_Or(i)),
[add_hyp (embed nseq) f1;add_hyp (embed nseq) f2]]
| Arrow (Conjunct (f1,f2),f0) ->
[make_step (SD_And(i)),
[add_hyp (embed nseq) (Arrow (f1,Arrow (f2,f0)))]]
| Arrow (Disjunct (f1,f2),f0) ->
[make_step (SD_Or(i)),
[add_hyp (add_hyp (embed nseq) (Arrow(f1,f0))) (Arrow (f2,f0))]]
| _ -> anomaly "search_in_rev_hyps: can't happen"
with
Not_found -> search_norev seq
let search_rev seq=
match seq.cnx with
(i,j,f1,f2)::next ->
let nseq=
match f1 with
Conjunct (_,_) | Disjunct (_,_) ->
{seq with cnx=next;
rev_hyps=Intmap.remove j seq.rev_hyps}
| Arrow (_,_) ->
{seq with cnx=next;
norev_hyps=Intmap.remove j seq.norev_hyps}
| _ ->
{seq with cnx=next} in
[{dep_it=SE_Arrow(i,j);
dep_goal=false;
dep_hyps=Intset.add i (Intset.singleton j)},
[add_hyp (embed nseq) f2]]
| [] ->
match seq.gl with
Arrow (f1,f2) ->
[{dep_it=SI_Arrow;
dep_goal=true;
dep_hyps=Intset.empty},
[add_hyp (change_goal (embed seq) f2) f1]]
| Conjunct (f1,f2) ->
[{dep_it=SI_And;
dep_goal=true;
dep_hyps=Intset.empty},[change_goal (embed seq) f1;
change_goal (embed seq) f2]]
| _ -> search_in_rev_hyps seq
let search_all seq=
match seq.abs with
Some i ->
[{dep_it=SE_False (i);
dep_goal=false;
dep_hyps=Intset.singleton i},[]]
| None ->
try
let ax = Fmap.find seq.gl seq.left in
[{dep_it=SAx (ax);
dep_goal=true;
dep_hyps=Intset.singleton ax},[]]
with Not_found -> search_rev seq
let bare_sequent = embed
{rev_hyps=Intmap.empty;
norev_hyps=Intmap.empty;
size=0;
left=Fmap.empty;
right=Fmap.empty;
cnx=[];
abs=None;
gl=Bot}
let init_state hyps gl=
let init = change_goal bare_sequent gl in
let goal=List.fold_right (fun (_,f,_) seq ->add_hyp seq f) hyps init in
Incomplete (goal.dep_it,[])
let success= function
Complete _ -> true
| Incomplete (_,_) -> false
let branching = function
Incomplete (seq,stack) ->
check_for_interrupt ();
let successors = search_all seq in
let _ =
match successors with
[] -> s_info.branch_failures<-s_info.branch_failures+1
| _::next ->
s_info.nd_branching<-s_info.nd_branching+List.length next in
List.map (append stack) successors
| Complete prf -> anomaly "already succeeded"
open Pp
let rec pp_form =
function
Arrow(f1,f2) -> (pp_or f1) ++ (str " -> ") ++ (pp_form f2)
| f -> pp_or f
and pp_or = function
Disjunct(f1,f2) ->
(pp_or f1) ++ (str " \\/ ") ++ (pp_and f2)
| f -> pp_and f
and pp_and = function
Conjunct(f1,f2) ->
(pp_and f1) ++ (str " /\\ ") ++ (pp_atom f2)
| f -> pp_atom f
and pp_atom= function
Bot -> str "#"
| Atom n -> int n
| f -> str "(" ++ hv 2 (pp_form f) ++ str ")"
let pr_form f = msg (pp_form f)
let pp_intmap map =
let pp=ref (str "") in
Intmap.iter (fun i obj -> pp:= (!pp ++
pp_form obj ++ cut ())) map;
str "{ " ++ v 0 (!pp) ++ str " }"
let pp_list pp_obj l=
let pp=ref (str "") in
List.iter (fun o -> pp := !pp ++ (pp_obj o) ++ str ", ") l;
str "[ " ++ !pp ++ str "]"
let pp_mapint map =
let pp=ref (str "") in
Fmap.iter (fun obj l -> pp:= (!pp ++
pp_form obj ++ str " => " ++
pp_list (fun (i,f) -> pp_form f) l ++
cut ()) ) map;
str "{ " ++ vb 0 ++ (!pp) ++ str " }" ++ close ()
let pp_connect (i,j,f1,f2) = pp_form f1 ++ str " => " ++ pp_form f2
let pp_gl gl= cut () ++
str "{ " ++ vb 0 ++
begin
match gl.abs with
None -> str ""
| Some i -> str "ABSURD" ++ cut ()
end ++
str "rev =" ++ pp_intmap gl.rev_hyps ++ cut () ++
str "norev =" ++ pp_intmap gl.norev_hyps ++ cut () ++
str "arrows=" ++ pp_mapint gl.right ++ cut () ++
str "cnx =" ++ pp_list pp_connect gl.cnx ++ cut () ++
str "goal =" ++ pp_form gl.gl ++ str " }" ++ close ()
let pp =
function
Incomplete(gl,ctx) -> pp_gl gl ++ fnl ()
| _ -> str "<complete>"
let pp_info () =
let count_info =
if !pruning then
str "Proof steps : " ++
int s_info.created_steps ++ str " created / " ++
int s_info.pruned_steps ++ str " pruned" ++ fnl () ++
str "Proof branches : " ++
int s_info.created_branches ++ str " created / " ++
int s_info.pruned_branches ++ str " pruned" ++ fnl () ++
str "Hypotheses : " ++
int s_info.created_hyps ++ str " created / " ++
int s_info.pruned_hyps ++ str " pruned" ++ fnl ()
else
str "Pruning is off" ++ fnl () ++
str "Proof steps : " ++
int s_info.created_steps ++ str " created" ++ fnl () ++
str "Proof branches : " ++
int s_info.created_branches ++ str " created" ++ fnl () ++
str "Hypotheses : " ++
int s_info.created_hyps ++ str " created" ++ fnl () in
msgnl
( str "Proof-search statistics :" ++ fnl () ++
count_info ++
str "Branch ends: " ++
int s_info.branch_successes ++ str " successes / " ++
int s_info.branch_failures ++ str " failures" ++ fnl () ++
str "Non-deterministic choices : " ++
int s_info.nd_branching ++ str " branches")
|