--- a/src/HOL/Tools/ATP/atp_proof_reconstruct.ML Thu Oct 18 11:59:45 2012 +0200
+++ b/src/HOL/Tools/ATP/atp_proof_reconstruct.ML Thu Oct 18 13:19:44 2012 +0200
@@ -3,36 +3,15 @@
Author: Claire Quigley, Cambridge University Computer Laboratory
Author: Jasmin Blanchette, TU Muenchen
-Proof reconstruction from ATP proofs.
+Basic proof reconstruction from ATP proofs.
*)
signature ATP_PROOF_RECONSTRUCT =
sig
type ('a, 'b) ho_term = ('a, 'b) ATP_Problem.ho_term
type ('a, 'b, 'c, 'd) formula = ('a, 'b, 'c, 'd) ATP_Problem.formula
- type 'a proof = 'a ATP_Proof.proof
- type stature = ATP_Problem_Generate.stature
-
- structure String_Redirect : ATP_PROOF_REDIRECT
-
- datatype reconstructor =
- Metis of string * string |
- SMT
-
- datatype play =
- Played of reconstructor * Time.time |
- Trust_Playable of reconstructor * Time.time option |
- Failed_to_Play of reconstructor
-
- type minimize_command = string list -> string
- type one_line_params =
- play * string * (string * stature) list * minimize_command * int * int
- type isar_params =
- bool * int * string Symtab.table * (string * stature) list vector
- * int Symtab.table * string proof * thm
val metisN : string
- val smtN : string
val full_typesN : string
val partial_typesN : string
val no_typesN : string
@@ -44,69 +23,14 @@
val partial_type_encs : string list
val metis_default_lam_trans : string
val metis_call : string -> string -> string
- val string_for_reconstructor : reconstructor -> string
- val used_facts_in_atp_proof :
- Proof.context -> (string * stature) list vector -> string proof
- -> (string * stature) list
- val lam_trans_from_atp_proof : string proof -> string -> string
- val is_typed_helper_used_in_atp_proof : string proof -> bool
- val used_facts_in_unsound_atp_proof :
- Proof.context -> (string * stature) list vector -> 'a proof
- -> string list option
val unalias_type_enc : string -> string list
- val one_line_proof_text : int -> one_line_params -> string
- val make_tvar : string -> typ
- val make_tfree : Proof.context -> string -> typ
+ val forall_of : term -> term -> term
val term_from_atp :
- Proof.context -> bool -> int Symtab.table -> typ option
- -> (string, string) ho_term -> term
+ Proof.context -> bool -> int Symtab.table -> typ option ->
+ (string, string) ho_term -> term
val prop_from_atp :
- Proof.context -> bool -> int Symtab.table
- -> (string, string, (string, string) ho_term, string) formula -> term
-
- type label
- type facts = label list * string list
-
- datatype isar_qualifier = Show | Then | Moreover | Ultimately
-
- datatype isar_step =
- Fix of (string * typ) list |
- Let of term * term |
- Assume of label * term |
- Prove of isar_qualifier list * label * term * byline
- and byline =
- By_Metis of facts |
- Case_Split of isar_step list list * facts
-
- val string_for_label : label -> string
- val decode_lines :
- Proof.context -> int Symtab.table
- -> (string, string, (string, string) ATP_Problem.ho_term, string)
- ATP_Problem.formula ATP_Proof.step list -> term ATP_Proof.step list
- val add_line :
- (string * 'a) list vector -> term ATP_Proof.step
- -> term ATP_Proof.step list -> term ATP_Proof.step list
- val repair_waldmeister_endgame : term ATP_Proof.step list -> term ATP_Proof.step list
- val add_desired_line :
- int -> (string * 'a) list vector -> (string * typ) list -> term ATP_Proof.step
- -> int * term ATP_Proof.step list -> int * term ATP_Proof.step list
- val add_nontrivial_line :
- term ATP_Proof.step -> term ATP_Proof.step list -> term ATP_Proof.step list
- val forall_of : term -> term -> term
- val raw_label_for_name : string * string list -> string * int
-
- val no_label : label
- val indent_size : int
- val reconstructor_command :
- reconstructor -> int -> int -> string list -> int
- -> (string * int) list * string list -> string
- val repair_name : string -> string
- val add_fact_from_dependency :
- (string * 'a) list vector -> string * string list
- -> (string * int) list * string list -> (string * int) list * string list
- val kill_duplicate_assumptions_in_proof : isar_step list -> isar_step list
- val kill_useless_labels_in_proof : isar_step list -> isar_step list
- val relabel_proof : isar_step list -> isar_step list
+ Proof.context -> bool -> int Symtab.table ->
+ (string, string, (string, string) ho_term, string) formula -> term
end;
structure ATP_Proof_Reconstruct : ATP_PROOF_RECONSTRUCT =
@@ -117,31 +41,7 @@
open ATP_Proof
open ATP_Problem_Generate
-structure String_Redirect = ATP_Proof_Redirect(
- type key = step_name
- val ord = fn ((s, _ : string list), (s', _)) => fast_string_ord (s, s')
- val string_of = fst)
-
-open String_Redirect
-
-datatype reconstructor =
- Metis of string * string |
- SMT
-
-datatype play =
- Played of reconstructor * Time.time |
- Trust_Playable of reconstructor * Time.time option |
- Failed_to_Play of reconstructor
-
-type minimize_command = string list -> string
-type one_line_params =
- play * string * (string * stature) list * minimize_command * int * int
-type isar_params =
- bool * int * string Symtab.table * (string * stature) list vector
- * int Symtab.table * string proof * thm
-
val metisN = "metis"
-val smtN = "smt"
val full_typesN = "full_types"
val partial_typesN = "partial_types"
@@ -176,212 +76,14 @@
|> lam_trans <> metis_default_lam_trans ? cons lam_trans
in metisN ^ (if null opts then "" else " (" ^ commas opts ^ ")") end
-fun string_for_reconstructor (Metis (type_enc, lam_trans)) =
- metis_call type_enc lam_trans
- | string_for_reconstructor SMT = smtN
-
-fun find_first_in_list_vector vec key =
- Vector.foldl (fn (ps, NONE) => AList.lookup (op =) ps key
- | (_, value) => value) NONE vec
-
-val unprefix_fact_number = space_implode "_" o tl o space_explode "_"
-
-fun resolve_one_named_fact fact_names s =
- case try (unprefix fact_prefix) s of
- SOME s' =>
- let val s' = s' |> unprefix_fact_number |> unascii_of in
- s' |> find_first_in_list_vector fact_names |> Option.map (pair s')
- end
- | NONE => NONE
-fun resolve_fact fact_names = map_filter (resolve_one_named_fact fact_names)
-fun is_fact fact_names = not o null o resolve_fact fact_names
-
-fun resolve_one_named_conjecture s =
- case try (unprefix conjecture_prefix) s of
- SOME s' => Int.fromString s'
- | NONE => NONE
-
-val resolve_conjecture = map_filter resolve_one_named_conjecture
-val is_conjecture = not o null o resolve_conjecture
-
-fun is_axiom_used_in_proof pred =
- exists (fn Inference_Step ((_, ss), _, _, []) => exists pred ss | _ => false)
-
-val is_combinator_def = String.isPrefix (helper_prefix ^ combinator_prefix)
-
-val ascii_of_lam_fact_prefix = ascii_of lam_fact_prefix
-
-(* overapproximation (good enough) *)
-fun is_lam_lifted s =
- String.isPrefix fact_prefix s andalso
- String.isSubstring ascii_of_lam_fact_prefix s
-
-fun lam_trans_from_atp_proof atp_proof default =
- case (is_axiom_used_in_proof is_combinator_def atp_proof,
- is_axiom_used_in_proof is_lam_lifted atp_proof) of
- (false, false) => default
- | (false, true) => liftingN
-(* | (true, true) => combs_and_liftingN -- not supported by "metis" *)
- | (true, _) => combsN
-
-val is_typed_helper_name =
- String.isPrefix helper_prefix andf String.isSuffix typed_helper_suffix
-fun is_typed_helper_used_in_atp_proof atp_proof =
- is_axiom_used_in_proof is_typed_helper_name atp_proof
-
-val leo2_ext = "extcnf_equal_neg"
-val leo2_unfold_def = "unfold_def"
-
-val isa_ext = Thm.get_name_hint @{thm ext}
-val isa_short_ext = Long_Name.base_name isa_ext
-
-fun ext_name ctxt =
- if Thm.eq_thm_prop (@{thm ext},
- singleton (Attrib.eval_thms ctxt) (Facts.named isa_short_ext, [])) then
- isa_short_ext
- else
- isa_ext
-
-fun add_non_rec_defs fact_names accum =
- Vector.foldl
- (fn (facts, facts') =>
- union (op =)
- (filter (fn (_, (_, status)) => status = Non_Rec_Def) facts)
- facts')
- accum fact_names
-
-fun add_fact ctxt fact_names (Inference_Step ((_, ss), _, rule, deps)) =
- (if rule = leo2_ext then
- insert (op =) (ext_name ctxt, (Global, General))
- else if rule = leo2_unfold_def then
- (* LEO 1.3.3 does not record definitions properly, leading to missing
- dependencies in the TSTP proof. Remove the next line once this is
- fixed. *)
- add_non_rec_defs fact_names
- else if rule = satallax_coreN then
- (fn [] =>
- (* Satallax doesn't include definitions in its unsatisfiable cores,
- so we assume the worst and include them all here. *)
- [(ext_name ctxt, (Global, General))] |> add_non_rec_defs fact_names
- | facts => facts)
- else
- I)
- #> (if null deps then union (op =) (resolve_fact fact_names ss)
- else I)
- | add_fact _ _ _ = I
-
-fun used_facts_in_atp_proof ctxt fact_names atp_proof =
- if null atp_proof then Vector.foldl (uncurry (union (op =))) [] fact_names
- else fold (add_fact ctxt fact_names) atp_proof []
-
-fun used_facts_in_unsound_atp_proof _ _ [] = NONE
- | used_facts_in_unsound_atp_proof ctxt fact_names atp_proof =
- let val used_facts = used_facts_in_atp_proof ctxt fact_names atp_proof in
- if forall (fn (_, (sc, _)) => sc = Global) used_facts andalso
- not (is_axiom_used_in_proof (is_conjecture o single) atp_proof) then
- SOME (map fst used_facts)
- else
- NONE
- end
-
-
-(** Soft-core proof reconstruction: one-liners **)
-
-fun string_for_label (s, num) = s ^ string_of_int num
-
-fun show_time NONE = ""
- | show_time (SOME ext_time) = " (" ^ string_from_ext_time ext_time ^ ")"
-
-fun unusing_chained_facts _ 0 = ""
- | unusing_chained_facts used_chaineds num_chained =
- if length used_chaineds = num_chained then ""
- else if null used_chaineds then "(* using no facts *) "
- else "(* using only " ^ space_implode " " used_chaineds ^ " *) "
-
-fun apply_on_subgoal _ 1 = "by "
- | apply_on_subgoal 1 _ = "apply "
- | apply_on_subgoal i n =
- "prefer " ^ string_of_int i ^ " " ^ apply_on_subgoal 1 n
-
-fun command_call name [] =
- name |> not (Lexicon.is_identifier name) ? enclose "(" ")"
- | command_call name args = "(" ^ name ^ " " ^ space_implode " " args ^ ")"
-
-fun try_command_line banner time command =
- banner ^ ": " ^ Markup.markup Isabelle_Markup.sendback command ^ show_time time ^ "."
-
-fun using_labels [] = ""
- | using_labels ls =
- "using " ^ space_implode " " (map string_for_label ls) ^ " "
-
-fun reconstructor_command reconstr i n used_chaineds num_chained (ls, ss) =
- unusing_chained_facts used_chaineds num_chained ^
- using_labels ls ^ apply_on_subgoal i n ^
- command_call (string_for_reconstructor reconstr) ss
-
-fun minimize_line _ [] = ""
- | minimize_line minimize_command ss =
- case minimize_command ss of
- "" => ""
- | command =>
- "\nTo minimize: " ^ Markup.markup Isabelle_Markup.sendback command ^ "."
-
-fun split_used_facts facts =
- facts |> List.partition (fn (_, (sc, _)) => sc = Chained)
- |> pairself (sort_distinct (string_ord o pairself fst))
-
-fun one_line_proof_text num_chained
- (preplay, banner, used_facts, minimize_command, subgoal,
- subgoal_count) =
- let
- val (chained, extra) = split_used_facts used_facts
- val (failed, reconstr, ext_time) =
- case preplay of
- Played (reconstr, time) => (false, reconstr, (SOME (false, time)))
- | Trust_Playable (reconstr, time) =>
- (false, reconstr,
- case time of
- NONE => NONE
- | SOME time =>
- if time = Time.zeroTime then NONE else SOME (true, time))
- | Failed_to_Play reconstr => (true, reconstr, NONE)
- val try_line =
- ([], map fst extra)
- |> reconstructor_command reconstr subgoal subgoal_count (map fst chained)
- num_chained
- |> (if failed then
- enclose "One-line proof reconstruction failed: "
- ".\n(Invoking \"sledgehammer\" with \"[strict]\" might \
- \solve this.)"
- else
- try_command_line banner ext_time)
- in try_line ^ minimize_line minimize_command (map fst (extra @ chained)) end
-
-(** Hard-core proof reconstruction: structured Isar proofs **)
-
fun forall_of v t = HOLogic.all_const (fastype_of v) $ lambda v t
fun exists_of v t = HOLogic.exists_const (fastype_of v) $ lambda v t
-fun make_tvar s = TVar (("'" ^ s, 0), HOLogic.typeS)
fun make_tfree ctxt w =
let val ww = "'" ^ w in
TFree (ww, the_default HOLogic.typeS (Variable.def_sort ctxt (ww, ~1)))
end
-val indent_size = 2
-val no_label = ("", ~1)
-
-val raw_prefix = "x"
-val assum_prefix = "a"
-val have_prefix = "f"
-
-fun raw_label_for_name (num, ss) =
- case resolve_conjecture ss of
- [j] => (conjecture_prefix, j)
- | _ => (raw_prefix ^ ascii_of num, 0)
-
-(**** INTERPRETATION OF TSTP SYNTAX TREES ****)
-
exception HO_TERM of (string, string) ho_term list
exception FORMULA of
(string, string, (string, string) ho_term, string) formula list
@@ -557,25 +259,6 @@
else
pair (term_from_atp ctxt textual sym_tab (SOME @{typ bool}) u)
-val combinator_table =
- [(@{const_name Meson.COMBI}, @{thm Meson.COMBI_def [abs_def]}),
- (@{const_name Meson.COMBK}, @{thm Meson.COMBK_def [abs_def]}),
- (@{const_name Meson.COMBB}, @{thm Meson.COMBB_def [abs_def]}),
- (@{const_name Meson.COMBC}, @{thm Meson.COMBC_def [abs_def]}),
- (@{const_name Meson.COMBS}, @{thm Meson.COMBS_def [abs_def]})]
-
-fun uncombine_term thy =
- let
- fun aux (t1 $ t2) = betapply (pairself aux (t1, t2))
- | aux (Abs (s, T, t')) = Abs (s, T, aux t')
- | aux (t as Const (x as (s, _))) =
- (case AList.lookup (op =) combinator_table s of
- SOME thm => thm |> prop_of |> specialize_type thy x
- |> Logic.dest_equals |> snd
- | NONE => t)
- | aux t = t
- in aux end
-
(* Update schematic type variables with detected sort constraints. It's not
totally clear whether this code is necessary. *)
fun repair_tvar_sorts (t, tvar_tab) =
@@ -608,10 +291,9 @@
| AQuant (q, (s, _) :: xs, phi') =>
do_formula pos (AQuant (q, xs, phi'))
(* FIXME: TFF *)
- #>> quantify_over_var (case q of
- AForall => forall_of
- | AExists => exists_of)
- (s |> textual ? repair_variable_name Char.toLower)
+ #>> quantify_over_var
+ (case q of AForall => forall_of | AExists => exists_of)
+ (s |> textual ? repair_variable_name Char.toLower)
| AConn (ANot, [phi']) => do_formula (not pos) phi' #>> s_not
| AConn (c, [phi1, phi2]) =>
do_formula (pos |> c = AImplies ? not) phi1
@@ -626,253 +308,4 @@
| _ => raise FORMULA [phi]
in repair_tvar_sorts (do_formula true phi Vartab.empty) end
-fun infer_formula_types ctxt =
- Type.constraint HOLogic.boolT
- #> Syntax.check_term
- (Proof_Context.set_mode Proof_Context.mode_schematic ctxt)
-
-fun uncombined_etc_prop_from_atp ctxt textual sym_tab =
- let val thy = Proof_Context.theory_of ctxt in
- prop_from_atp ctxt textual sym_tab
- #> textual ? uncombine_term thy #> infer_formula_types ctxt
- end
-
-(**** Translation of TSTP files to Isar proofs ****)
-
-fun unvarify_term (Var ((s, 0), T)) = Free (s, T)
- | unvarify_term t = raise TERM ("unvarify_term: non-Var", [t])
-
-fun decode_line sym_tab (Definition_Step (name, phi1, phi2)) ctxt =
- let
- val thy = Proof_Context.theory_of ctxt
- val t1 = prop_from_atp ctxt true sym_tab phi1
- val vars = snd (strip_comb t1)
- val frees = map unvarify_term vars
- val unvarify_args = subst_atomic (vars ~~ frees)
- val t2 = prop_from_atp ctxt true sym_tab phi2
- val (t1, t2) =
- HOLogic.eq_const HOLogic.typeT $ t1 $ t2
- |> unvarify_args |> uncombine_term thy |> infer_formula_types ctxt
- |> HOLogic.dest_eq
- in
- (Definition_Step (name, t1, t2),
- fold Variable.declare_term (maps Misc_Legacy.term_frees [t1, t2]) ctxt)
- end
- | decode_line sym_tab (Inference_Step (name, u, rule, deps)) ctxt =
- let val t = u |> uncombined_etc_prop_from_atp ctxt true sym_tab in
- (Inference_Step (name, t, rule, deps),
- fold Variable.declare_term (Misc_Legacy.term_frees t) ctxt)
- end
-fun decode_lines ctxt sym_tab lines =
- fst (fold_map (decode_line sym_tab) lines ctxt)
-
-fun is_same_inference _ (Definition_Step _) = false
- | is_same_inference t (Inference_Step (_, t', _, _)) = t aconv t'
-
-(* No "real" literals means only type information (tfree_tcs, clsrel, or
- clsarity). *)
-fun is_only_type_information t = t aconv @{term True}
-
-fun replace_one_dependency (old, new) dep =
- if is_same_atp_step dep old then new else [dep]
-fun replace_dependencies_in_line _ (line as Definition_Step _) = line
- | replace_dependencies_in_line p (Inference_Step (name, t, rule, deps)) =
- Inference_Step (name, t, rule,
- fold (union (op =) o replace_one_dependency p) deps [])
-
-(* Discard facts; consolidate adjacent lines that prove the same formula, since
- they differ only in type information.*)
-fun add_line _ (line as Definition_Step _) lines = line :: lines
- | add_line fact_names (Inference_Step (name as (_, ss), t, rule, [])) lines =
- (* No dependencies: fact, conjecture, or (for Vampire) internal facts or
- definitions. *)
- if is_fact fact_names ss then
- (* Facts are not proof lines. *)
- if is_only_type_information t then
- map (replace_dependencies_in_line (name, [])) lines
- (* Is there a repetition? If so, replace later line by earlier one. *)
- else case take_prefix (not o is_same_inference t) lines of
- (_, []) => lines (* no repetition of proof line *)
- | (pre, Inference_Step (name', _, _, _) :: post) =>
- pre @ map (replace_dependencies_in_line (name', [name])) post
- | _ => raise Fail "unexpected inference"
- else if is_conjecture ss then
- Inference_Step (name, t, rule, []) :: lines
- else
- map (replace_dependencies_in_line (name, [])) lines
- | add_line _ (Inference_Step (name, t, rule, deps)) lines =
- (* Type information will be deleted later; skip repetition test. *)
- if is_only_type_information t then
- Inference_Step (name, t, rule, deps) :: lines
- (* Is there a repetition? If so, replace later line by earlier one. *)
- else case take_prefix (not o is_same_inference t) lines of
- (* FIXME: Doesn't this code risk conflating proofs involving different
- types? *)
- (_, []) => Inference_Step (name, t, rule, deps) :: lines
- | (pre, Inference_Step (name', t', rule, _) :: post) =>
- Inference_Step (name, t', rule, deps) ::
- pre @ map (replace_dependencies_in_line (name', [name])) post
- | _ => raise Fail "unexpected inference"
-
-val waldmeister_conjecture_num = "1.0.0.0"
-
-val repair_waldmeister_endgame =
- let
- fun do_tail (Inference_Step (name, t, rule, deps)) =
- Inference_Step (name, s_not t, rule, deps)
- | do_tail line = line
- fun do_body [] = []
- | do_body ((line as Inference_Step ((num, _), _, _, _)) :: lines) =
- if num = waldmeister_conjecture_num then map do_tail (line :: lines)
- else line :: do_body lines
- | do_body (line :: lines) = line :: do_body lines
- in do_body end
-
-(* Recursively delete empty lines (type information) from the proof. *)
-fun add_nontrivial_line (line as Inference_Step (name, t, _, [])) lines =
- if is_only_type_information t then delete_dependency name lines
- else line :: lines
- | add_nontrivial_line line lines = line :: lines
-and delete_dependency name lines =
- fold_rev add_nontrivial_line
- (map (replace_dependencies_in_line (name, [])) lines) []
-
-(* ATPs sometimes reuse free variable names in the strangest ways. Removing
- offending lines often does the trick. *)
-fun is_bad_free frees (Free x) = not (member (op =) frees x)
- | is_bad_free _ _ = false
-
-fun add_desired_line _ _ _ (line as Definition_Step (name, _, _)) (j, lines) =
- (j, line :: map (replace_dependencies_in_line (name, [])) lines)
- | add_desired_line isar_shrink_factor fact_names frees
- (Inference_Step (name as (_, ss), t, rule, deps)) (j, lines) =
- (j + 1,
- if is_fact fact_names ss orelse
- is_conjecture ss orelse
- (* the last line must be kept *)
- j = 0 orelse
- (not (is_only_type_information t) andalso
- null (Term.add_tvars t []) andalso
- not (exists_subterm (is_bad_free frees) t) andalso
- length deps >= 2 andalso j mod isar_shrink_factor = 0 andalso
- (* kill next to last line, which usually results in a trivial step *)
- j <> 1) then
- Inference_Step (name, t, rule, deps) :: lines (* keep line *)
- else
- map (replace_dependencies_in_line (name, deps)) lines) (* drop line *)
-
-(** Isar proof construction and manipulation **)
-
-type label = string * int
-type facts = label list * string list
-
-datatype isar_qualifier = Show | Then | Moreover | Ultimately
-
-datatype isar_step =
- Fix of (string * typ) list |
- Let of term * term |
- Assume of label * term |
- Prove of isar_qualifier list * label * term * byline
-and byline =
- By_Metis of facts |
- Case_Split of isar_step list list * facts
-
-fun add_fact_from_dependency fact_names (name as (_, ss)) =
- if is_fact fact_names ss then
- apsnd (union (op =) (map fst (resolve_fact fact_names ss)))
- else
- apfst (insert (op =) (raw_label_for_name name))
-
-fun repair_name "$true" = "c_True"
- | repair_name "$false" = "c_False"
- | repair_name "$$e" = tptp_equal (* seen in Vampire proofs *)
- | repair_name s =
- if is_tptp_equal s orelse
- (* seen in Vampire proofs *)
- (String.isPrefix "sQ" s andalso String.isSuffix "_eqProxy" s) then
- tptp_equal
- else
- s
-
-(* FIXME: Still needed? Try with SPASS proofs perhaps. *)
-val kill_duplicate_assumptions_in_proof =
- let
- fun relabel_facts subst =
- apfst (map (fn l => AList.lookup (op =) subst l |> the_default l))
- fun do_step (step as Assume (l, t)) (proof, subst, assums) =
- (case AList.lookup (op aconv) assums t of
- SOME l' => (proof, (l, l') :: subst, assums)
- | NONE => (step :: proof, subst, (t, l) :: assums))
- | do_step (Prove (qs, l, t, by)) (proof, subst, assums) =
- (Prove (qs, l, t,
- case by of
- By_Metis facts => By_Metis (relabel_facts subst facts)
- | Case_Split (proofs, facts) =>
- Case_Split (map do_proof proofs,
- relabel_facts subst facts)) ::
- proof, subst, assums)
- | do_step step (proof, subst, assums) = (step :: proof, subst, assums)
- and do_proof proof = fold do_step proof ([], [], []) |> #1 |> rev
- in do_proof end
-
-fun used_labels_of_step (Prove (_, _, _, by)) =
- (case by of
- By_Metis (ls, _) => ls
- | Case_Split (proofs, (ls, _)) =>
- fold (union (op =) o used_labels_of) proofs ls)
- | used_labels_of_step _ = []
-and used_labels_of proof = fold (union (op =) o used_labels_of_step) proof []
-
-fun kill_useless_labels_in_proof proof =
- let
- val used_ls = used_labels_of proof
- fun do_label l = if member (op =) used_ls l then l else no_label
- fun do_step (Assume (l, t)) = Assume (do_label l, t)
- | do_step (Prove (qs, l, t, by)) =
- Prove (qs, do_label l, t,
- case by of
- Case_Split (proofs, facts) =>
- Case_Split (map (map do_step) proofs, facts)
- | _ => by)
- | do_step step = step
- in map do_step proof end
-
-fun prefix_for_depth n = replicate_string (n + 1)
-
-val relabel_proof =
- let
- fun aux _ _ _ [] = []
- | aux subst depth (next_assum, next_fact) (Assume (l, t) :: proof) =
- if l = no_label then
- Assume (l, t) :: aux subst depth (next_assum, next_fact) proof
- else
- let val l' = (prefix_for_depth depth assum_prefix, next_assum) in
- Assume (l', t) ::
- aux ((l, l') :: subst) depth (next_assum + 1, next_fact) proof
- end
- | aux subst depth (next_assum, next_fact)
- (Prove (qs, l, t, by) :: proof) =
- let
- val (l', subst, next_fact) =
- if l = no_label then
- (l, subst, next_fact)
- else
- let
- val l' = (prefix_for_depth depth have_prefix, next_fact)
- in (l', (l, l') :: subst, next_fact + 1) end
- val relabel_facts =
- apfst (maps (the_list o AList.lookup (op =) subst))
- val by =
- case by of
- By_Metis facts => By_Metis (relabel_facts facts)
- | Case_Split (proofs, facts) =>
- Case_Split (map (aux subst (depth + 1) (1, 1)) proofs,
- relabel_facts facts)
- in
- Prove (qs, l', t, by) :: aux subst depth (next_assum, next_fact) proof
- end
- | aux subst depth nextp (step :: proof) =
- step :: aux subst depth nextp proof
- in aux [] 0 (1, 1) end
-
end;