* Metis: the maximum number of clauses that can be produced from a theorem is now given by the attribute max_clauses. Theorems that exceed this number are ignored, with a warning printed.
--- a/NEWS Mon Apr 07 15:37:04 2008 +0200
+++ b/NEWS Mon Apr 07 15:37:27 2008 +0200
@@ -173,6 +173,8 @@
* Metis prover is now an order of magnitude faster, and also works
with multithreading.
+* Metis: the maximum number of clauses that can be produced from a theorem is now given by the attribute max_clauses. Theorems that exceed this number are ignored, with a warning printed.
+
* Sledgehammer no longer produces structured proofs by default. To enable,
declare [[sledgehammer_full = true]]. Attributes reconstruction_modulus,
reconstruction_sorts renamed sledgehammer_modulus, sledgehammer_sorts.
--- a/src/HOL/Hilbert_Choice.thy Mon Apr 07 15:37:04 2008 +0200
+++ b/src/HOL/Hilbert_Choice.thy Mon Apr 07 15:37:27 2008 +0200
@@ -635,6 +635,8 @@
use "Tools/meson.ML"
+setup Meson.setup
+
subsection {* Specification package -- Hilbertized version *}
--- a/src/HOL/Tools/meson.ML Mon Apr 07 15:37:04 2008 +0200
+++ b/src/HOL/Tools/meson.ML Mon Apr 07 15:37:27 2008 +0200
@@ -14,7 +14,7 @@
val first_order_resolve: thm -> thm -> thm
val flexflex_first_order: thm -> thm
val size_of_subgoals: thm -> int
- val too_many_clauses: term -> bool
+ val too_many_clauses: Proof.context option -> term -> bool
val make_cnf: thm list -> thm -> Proof.context -> thm list * Proof.context
val finish_cnf: thm list -> thm list
val make_nnf: thm -> thm
@@ -41,11 +41,15 @@
val negate_head: thm -> thm
val select_literal: int -> thm -> thm
val skolemize_tac: int -> tactic
+ val setup: Context.theory -> Context.theory
end
structure Meson: MESON =
struct
+val max_clauses_default = 60;
+val (max_clauses, setup) = Attrib.config_int "max_clauses" max_clauses_default;
+
val not_conjD = thm "meson_not_conjD";
val not_disjD = thm "meson_not_disjD";
val not_notD = thm "meson_not_notD";
@@ -237,37 +241,39 @@
(*** The basic CNF transformation ***)
-val max_clauses = 40;
-
-fun sum x y = if x < max_clauses andalso y < max_clauses then x+y else max_clauses;
-fun prod x y = if x < max_clauses andalso y < max_clauses then x*y else max_clauses;
-
-(*Estimate the number of clauses in order to detect infeasible theorems*)
-fun signed_nclauses b (Const("Trueprop",_) $ t) = signed_nclauses b t
- | signed_nclauses b (Const("Not",_) $ t) = signed_nclauses (not b) t
- | signed_nclauses b (Const("op &",_) $ t $ u) =
- if b then sum (signed_nclauses b t) (signed_nclauses b u)
- else prod (signed_nclauses b t) (signed_nclauses b u)
- | signed_nclauses b (Const("op |",_) $ t $ u) =
- if b then prod (signed_nclauses b t) (signed_nclauses b u)
- else sum (signed_nclauses b t) (signed_nclauses b u)
- | signed_nclauses b (Const("op -->",_) $ t $ u) =
- if b then prod (signed_nclauses (not b) t) (signed_nclauses b u)
- else sum (signed_nclauses (not b) t) (signed_nclauses b u)
- | signed_nclauses b (Const("op =", Type ("fun", [T, _])) $ t $ u) =
- if T = HOLogic.boolT then (*Boolean equality is if-and-only-if*)
- if b then sum (prod (signed_nclauses (not b) t) (signed_nclauses b u))
- (prod (signed_nclauses (not b) u) (signed_nclauses b t))
- else sum (prod (signed_nclauses b t) (signed_nclauses b u))
- (prod (signed_nclauses (not b) t) (signed_nclauses (not b) u))
- else 1
- | signed_nclauses b (Const("Ex", _) $ Abs (_,_,t)) = signed_nclauses b t
- | signed_nclauses b (Const("All",_) $ Abs (_,_,t)) = signed_nclauses b t
- | signed_nclauses _ _ = 1; (* literal *)
-
-val nclauses = signed_nclauses true;
-
-fun too_many_clauses t = nclauses t >= max_clauses;
+fun too_many_clauses ctxto t =
+ let
+ val max_cl = case ctxto of SOME ctxt => Config.get ctxt max_clauses
+ | NONE => max_clauses_default
+
+ fun sum x y = if x < max_cl andalso y < max_cl then x+y else max_cl;
+ fun prod x y = if x < max_cl andalso y < max_cl then x*y else max_cl;
+
+ (*Estimate the number of clauses in order to detect infeasible theorems*)
+ fun signed_nclauses b (Const("Trueprop",_) $ t) = signed_nclauses b t
+ | signed_nclauses b (Const("Not",_) $ t) = signed_nclauses (not b) t
+ | signed_nclauses b (Const("op &",_) $ t $ u) =
+ if b then sum (signed_nclauses b t) (signed_nclauses b u)
+ else prod (signed_nclauses b t) (signed_nclauses b u)
+ | signed_nclauses b (Const("op |",_) $ t $ u) =
+ if b then prod (signed_nclauses b t) (signed_nclauses b u)
+ else sum (signed_nclauses b t) (signed_nclauses b u)
+ | signed_nclauses b (Const("op -->",_) $ t $ u) =
+ if b then prod (signed_nclauses (not b) t) (signed_nclauses b u)
+ else sum (signed_nclauses (not b) t) (signed_nclauses b u)
+ | signed_nclauses b (Const("op =", Type ("fun", [T, _])) $ t $ u) =
+ if T = HOLogic.boolT then (*Boolean equality is if-and-only-if*)
+ if b then sum (prod (signed_nclauses (not b) t) (signed_nclauses b u))
+ (prod (signed_nclauses (not b) u) (signed_nclauses b t))
+ else sum (prod (signed_nclauses b t) (signed_nclauses b u))
+ (prod (signed_nclauses (not b) t) (signed_nclauses (not b) u))
+ else 1
+ | signed_nclauses b (Const("Ex", _) $ Abs (_,_,t)) = signed_nclauses b t
+ | signed_nclauses b (Const("All",_) $ Abs (_,_,t)) = signed_nclauses b t
+ | signed_nclauses _ _ = 1; (* literal *)
+ in
+ signed_nclauses true t >= max_cl
+ end;
(*Replaces universally quantified variables by FREE variables -- because
assumptions may not contain scheme variables. Later, generalize using Variable.export. *)
@@ -328,8 +334,8 @@
| _ => nodups th :: ths (*no work to do*)
and cnf_nil th = cnf_aux (th,[])
val cls =
- if too_many_clauses (concl_of th)
- then (Output.debug (fn () => ("cnf is ignoring: " ^ string_of_thm th)); ths)
+ if too_many_clauses (SOME ctxt) (concl_of th)
+ then (warning ("cnf is ignoring: " ^ string_of_thm th); ths)
else cnf_aux (th,ths)
in (cls, !ctxtr) end;
--- a/src/HOL/Tools/res_axioms.ML Mon Apr 07 15:37:04 2008 +0200
+++ b/src/HOL/Tools/res_axioms.ML Mon Apr 07 15:37:27 2008 +0200
@@ -339,7 +339,7 @@
fun too_complex t =
apply_depth t > max_apply_depth orelse
- Meson.too_many_clauses t orelse
+ Meson.too_many_clauses NONE t orelse
excessive_lambdas_fm [] t;
fun is_strange_thm th =