(* Title: Pure/Isar/method.ML
Author: Markus Wenzel, TU Muenchen
Isar proof methods.
*)
signature BASIC_METHOD =
sig
val FINDGOAL: (int -> thm -> 'a Seq.seq) -> thm -> 'a Seq.seq
val HEADGOAL: (int -> thm -> 'a Seq.seq) -> thm -> 'a Seq.seq
val rule_trace: bool Config.T
end;
signature METHOD =
sig
include BASIC_METHOD
type method
val apply: (Proof.context -> method) -> Proof.context -> thm list -> cases_tactic
val RAW_METHOD_CASES: (thm list -> cases_tactic) -> method
val RAW_METHOD: (thm list -> tactic) -> method
val METHOD_CASES: (thm list -> cases_tactic) -> method
val METHOD: (thm list -> tactic) -> method
val fail: method
val succeed: method
val insert_tac: thm list -> int -> tactic
val insert: thm list -> method
val insert_facts: method
val SIMPLE_METHOD: tactic -> method
val SIMPLE_METHOD': (int -> tactic) -> method
val SIMPLE_METHOD'': ((int -> tactic) -> tactic) -> (int -> tactic) -> method
val defer: int option -> method
val prefer: int -> method
val cheating: bool -> Proof.context -> method
val intro: thm list -> method
val elim: thm list -> method
val unfold: thm list -> Proof.context -> method
val fold: thm list -> Proof.context -> method
val atomize: bool -> method
val this: method
val fact: thm list -> Proof.context -> method
val assm_tac: Proof.context -> int -> tactic
val all_assm_tac: Proof.context -> tactic
val assumption: Proof.context -> method
val close: bool -> Proof.context -> method
val trace: Proof.context -> thm list -> unit
val rule_tac: thm list -> thm list -> int -> tactic
val some_rule_tac: thm list -> Proof.context -> thm list -> int -> tactic
val intros_tac: thm list -> thm list -> tactic
val try_intros_tac: thm list -> thm list -> tactic
val rule: thm list -> method
val erule: int -> thm list -> method
val drule: int -> thm list -> method
val frule: int -> thm list -> method
val set_tactic: (thm list -> tactic) -> Proof.context -> Proof.context
val tactic: string * Position.T -> Proof.context -> method
val raw_tactic: string * Position.T -> Proof.context -> method
type src = Args.src
datatype text =
Basic of Proof.context -> method |
Source of src |
Source_i of src |
Then of text list |
Orelse of text list |
Try of text |
Repeat1 of text |
SelectGoals of int * text
val primitive_text: (thm -> thm) -> text
val succeed_text: text
val default_text: text
val this_text: text
val done_text: text
val sorry_text: bool -> text
val finish_text: text option * bool -> text
val print_methods: theory -> unit
val intern: theory -> xstring -> string
val defined: theory -> string -> bool
val method: theory -> src -> Proof.context -> method
val method_i: theory -> src -> Proof.context -> method
val syntax: 'a context_parser -> src -> Proof.context -> 'a * Proof.context
val setup: binding -> (Proof.context -> method) context_parser -> string -> theory -> theory
val method_setup: bstring * Position.T -> Symbol_Pos.text * Position.T -> string ->
theory -> theory
type modifier = (Proof.context -> Proof.context) * attribute
val section: modifier parser list -> thm list context_parser
val sections: modifier parser list -> thm list list context_parser
val parse: text parser
end;
structure Method: METHOD =
struct
(** generic tools **)
(* goal addressing *)
fun FINDGOAL tac st =
let fun find i n = if i > n then Seq.fail else Seq.APPEND (tac i, find (i + 1) n)
in find 1 (Thm.nprems_of st) st end;
fun HEADGOAL tac = tac 1;
(** proof methods **)
(* datatype method *)
datatype method = Meth of thm list -> cases_tactic;
fun apply meth ctxt = let val Meth m = meth ctxt in m end;
val RAW_METHOD_CASES = Meth;
fun RAW_METHOD tac = RAW_METHOD_CASES (NO_CASES o tac);
fun METHOD_CASES tac = RAW_METHOD_CASES (fn facts =>
Seq.THEN (ALLGOALS Goal.conjunction_tac, tac facts));
fun METHOD tac = RAW_METHOD (fn facts => ALLGOALS Goal.conjunction_tac THEN tac facts);
val fail = METHOD (K no_tac);
val succeed = METHOD (K all_tac);
(* insert facts *)
local
fun cut_rule_tac rule =
Tactic.rtac (Drule.forall_intr_vars rule COMP_INCR revcut_rl);
in
fun insert_tac [] i = all_tac
| insert_tac facts i = EVERY (map (fn th => cut_rule_tac th i) facts);
val insert_facts = METHOD (ALLGOALS o insert_tac);
fun insert thms = METHOD (fn _ => ALLGOALS (insert_tac thms));
fun SIMPLE_METHOD tac = METHOD (fn facts => ALLGOALS (insert_tac facts) THEN tac);
fun SIMPLE_METHOD'' quant tac = METHOD (fn facts => quant (insert_tac facts THEN' tac));
val SIMPLE_METHOD' = SIMPLE_METHOD'' HEADGOAL;
end;
(* shuffle subgoals *)
fun prefer i = METHOD (K (Tactic.defer_tac i THEN PRIMITIVE (Thm.permute_prems 0 ~1)));
fun defer opt_i = METHOD (K (Tactic.defer_tac (the_default 1 opt_i)));
(* cheating *)
fun cheating int ctxt =
if int orelse ! quick_and_dirty then
METHOD (K (Skip_Proof.cheat_tac (Proof_Context.theory_of ctxt)))
else error "Cheating requires quick_and_dirty mode!";
(* unfold intro/elim rules *)
fun intro ths = SIMPLE_METHOD' (CHANGED_PROP o REPEAT_ALL_NEW (Tactic.match_tac ths));
fun elim ths = SIMPLE_METHOD' (CHANGED_PROP o REPEAT_ALL_NEW (Tactic.ematch_tac ths));
(* unfold/fold definitions *)
fun unfold_meth ths ctxt = SIMPLE_METHOD (CHANGED_PROP (Local_Defs.unfold_tac ctxt ths));
fun fold_meth ths ctxt = SIMPLE_METHOD (CHANGED_PROP (Local_Defs.fold_tac ctxt ths));
(* atomize rule statements *)
fun atomize false = SIMPLE_METHOD' (CHANGED_PROP o Object_Logic.atomize_prems_tac)
| atomize true = RAW_METHOD (K (HEADGOAL (CHANGED_PROP o Object_Logic.full_atomize_tac)));
(* this -- resolve facts directly *)
val this = METHOD (EVERY o map (HEADGOAL o Tactic.rtac));
(* fact -- composition by facts from context *)
fun fact [] ctxt = SIMPLE_METHOD' (Proof_Context.some_fact_tac ctxt)
| fact rules _ = SIMPLE_METHOD' (Proof_Context.fact_tac rules);
(* assumption *)
local
fun cond_rtac cond rule = SUBGOAL (fn (prop, i) =>
if cond (Logic.strip_assums_concl prop)
then Tactic.rtac rule i else no_tac);
in
fun assm_tac ctxt =
assume_tac APPEND'
Goal.assume_rule_tac ctxt APPEND'
cond_rtac (can Logic.dest_equals) Drule.reflexive_thm APPEND'
cond_rtac (can Logic.dest_term) Drule.termI;
fun all_assm_tac ctxt st = EVERY1 (replicate (Thm.nprems_of st) (assm_tac ctxt)) st;
fun assumption ctxt = METHOD (HEADGOAL o
(fn [] => assm_tac ctxt
| [fact] => solve_tac [fact]
| _ => K no_tac));
fun close immed ctxt = METHOD (K
(FILTER Thm.no_prems ((if immed then all_assm_tac ctxt else all_tac) THEN flexflex_tac)));
end;
(* rule etc. -- single-step refinements *)
val rule_trace = Attrib.setup_config_bool (Binding.name "rule_trace") (fn _ => false);
fun trace ctxt rules =
if Config.get ctxt rule_trace andalso not (null rules) then
Pretty.big_list "rules:" (map (Display.pretty_thm ctxt) rules)
|> Pretty.string_of |> tracing
else ();
local
fun gen_rule_tac tac rules facts =
(fn i => fn st =>
if null facts then tac rules i st
else Seq.maps (fn rule => (tac o single) rule i st) (Drule.multi_resolves facts rules))
THEN_ALL_NEW Goal.norm_hhf_tac;
fun gen_arule_tac tac j rules facts =
EVERY' (gen_rule_tac tac rules facts :: replicate j Tactic.assume_tac);
fun gen_some_rule_tac tac arg_rules ctxt facts = SUBGOAL (fn (goal, i) =>
let
val rules =
if not (null arg_rules) then arg_rules
else flat (Context_Rules.find_rules false facts goal ctxt)
in trace ctxt rules; tac rules facts i end);
fun meth tac x = METHOD (HEADGOAL o tac x);
fun meth' tac x y = METHOD (HEADGOAL o tac x y);
in
val rule_tac = gen_rule_tac Tactic.resolve_tac;
val rule = meth rule_tac;
val some_rule_tac = gen_some_rule_tac rule_tac;
val some_rule = meth' some_rule_tac;
val erule = meth' (gen_arule_tac Tactic.eresolve_tac);
val drule = meth' (gen_arule_tac Tactic.dresolve_tac);
val frule = meth' (gen_arule_tac Tactic.forward_tac);
end;
(* intros_tac -- pervasive search spanned by intro rules *)
fun gen_intros_tac goals intros facts =
goals (insert_tac facts THEN'
REPEAT_ALL_NEW (resolve_tac intros))
THEN Tactic.distinct_subgoals_tac;
val intros_tac = gen_intros_tac ALLGOALS;
val try_intros_tac = gen_intros_tac TRYALL;
(* ML tactics *)
structure ML_Tactic = Proof_Data
(
type T = thm list -> tactic;
fun init _ = undefined;
);
val set_tactic = ML_Tactic.put;
fun ml_tactic (txt, pos) ctxt =
let
val ctxt' = ctxt |> Context.proof_map
(ML_Context.expression pos
"fun tactic (facts: thm list) : tactic"
"Context.map_proof (Method.set_tactic tactic)" (ML_Lex.read pos txt));
in Context.setmp_thread_data (SOME (Context.Proof ctxt)) (ML_Tactic.get ctxt') end;
fun tactic txt ctxt = METHOD (ml_tactic txt ctxt);
fun raw_tactic txt ctxt = RAW_METHOD (ml_tactic txt ctxt);
(** method syntax **)
(* method text *)
type src = Args.src;
datatype text =
Basic of Proof.context -> method |
Source of src |
Source_i of src |
Then of text list |
Orelse of text list |
Try of text |
Repeat1 of text |
SelectGoals of int * text;
fun primitive_text r = Basic (K (SIMPLE_METHOD (PRIMITIVE r)));
val succeed_text = Basic (K succeed);
val default_text = Source (Args.src (("default", []), Position.none));
val this_text = Basic (K this);
val done_text = Basic (K (SIMPLE_METHOD all_tac));
fun sorry_text int = Basic (cheating int);
fun finish_text (NONE, immed) = Basic (close immed)
| finish_text (SOME txt, immed) = Then [txt, Basic (close immed)];
(* method definitions *)
structure Methods = Theory_Data
(
type T = ((src -> Proof.context -> method) * string) Name_Space.table;
val empty : T = Name_Space.empty_table "method";
val extend = I;
fun merge data : T = Name_Space.merge_tables data;
);
fun print_methods thy =
let
val ctxt = Proof_Context.init_global thy;
val meths = Methods.get thy;
fun prt_meth (name, (_, "")) = Pretty.str name
| prt_meth (name, (_, comment)) =
Pretty.block [Pretty.str (name ^ ":"), Pretty.brk 2, Pretty.str comment];
in
[Pretty.big_list "methods:" (map prt_meth (Name_Space.extern_table ctxt meths))]
|> Pretty.chunks |> Pretty.writeln
end;
fun add_method name meth comment thy = thy
|> Methods.map
(Name_Space.define (Proof_Context.init_global thy) true (Sign.naming_of thy)
(name, (meth, comment)) #> snd);
(* get methods *)
val intern = Name_Space.intern o #1 o Methods.get;
val defined = Symtab.defined o #2 o Methods.get;
fun method_i thy =
let
val (space, tab) = Methods.get thy;
fun meth src =
let val ((name, _), pos) = Args.dest_src src in
(case Symtab.lookup tab name of
NONE => error ("Unknown proof method: " ^ quote name ^ Position.str_of pos)
| SOME (mth, _) => (Position.report pos (Name_Space.markup space name); mth src))
end;
in meth end;
fun method thy = method_i thy o Args.map_name (Name_Space.intern (#1 (Methods.get thy)));
(* method setup *)
fun syntax scan = Args.context_syntax "method" scan;
fun setup name scan =
add_method name
(fn src => fn ctxt => let val (m, ctxt') = syntax scan src ctxt in m ctxt' end);
fun method_setup name (txt, pos) cmt =
Context.theory_map (ML_Context.expression pos
"val (name, scan, comment): binding * (Proof.context -> Proof.method) context_parser * string"
"Context.map_theory (Method.setup name scan comment)"
(ML_Lex.read Position.none ("(" ^ ML_Syntax.make_binding name ^ ", ") @
ML_Lex.read pos txt @
ML_Lex.read Position.none (", " ^ ML_Syntax.print_string cmt ^ ")")));
(** concrete syntax **)
(* sections *)
type modifier = (Proof.context -> Proof.context) * attribute;
local
fun thms ss = Scan.repeat (Scan.unless (Scan.lift (Scan.first ss)) Attrib.multi_thm) >> flat;
fun app (f, att) (context, ths) = Library.foldl_map att (Context.map_proof f context, ths);
in
fun section ss = Scan.depend (fn context => (Scan.first ss -- Scan.pass context (thms ss)) :|--
(fn (m, ths) => Scan.succeed (app m (context, ths))));
fun sections ss = Scan.repeat (section ss);
end;
(* extra rule methods *)
fun xrule_meth m =
Scan.lift (Scan.optional (Args.parens Parse.nat) 0) -- Attrib.thms >>
(fn (n, ths) => K (m n ths));
(* outer parser *)
fun is_symid_meth s =
s <> "|" andalso s <> "?" andalso s <> "+" andalso Token.ident_or_symbolic s;
local
fun meth4 x =
(Parse.position (Parse.xname >> rpair []) >> (Source o Args.src) ||
Parse.$$$ "(" |-- Parse.!!! (meth0 --| Parse.$$$ ")")) x
and meth3 x =
(meth4 --| Parse.$$$ "?" >> Try ||
meth4 --| Parse.$$$ "+" >> Repeat1 ||
meth4 -- (Parse.$$$ "[" |-- Scan.optional Parse.nat 1 --| Parse.$$$ "]") >> (SelectGoals o swap) ||
meth4) x
and meth2 x =
(Parse.position (Parse.xname -- Args.parse1 is_symid_meth) >> (Source o Args.src) ||
meth3) x
and meth1 x = (Parse.enum1 "," meth2 >> (fn [m] => m | ms => Then ms)) x
and meth0 x = (Parse.enum1 "|" meth1 >> (fn [m] => m | ms => Orelse ms)) x;
in val parse = meth3 end;
(* theory setup *)
val _ = Context.>> (Context.map_theory
(setup (Binding.name "fail") (Scan.succeed (K fail)) "force failure" #>
setup (Binding.name "succeed") (Scan.succeed (K succeed)) "succeed" #>
setup (Binding.name "-") (Scan.succeed (K insert_facts))
"do nothing (insert current facts only)" #>
setup (Binding.name "insert") (Attrib.thms >> (K o insert))
"insert theorems, ignoring facts (improper)" #>
setup (Binding.name "intro") (Attrib.thms >> (K o intro))
"repeatedly apply introduction rules" #>
setup (Binding.name "elim") (Attrib.thms >> (K o elim))
"repeatedly apply elimination rules" #>
setup (Binding.name "unfold") (Attrib.thms >> unfold_meth) "unfold definitions" #>
setup (Binding.name "fold") (Attrib.thms >> fold_meth) "fold definitions" #>
setup (Binding.name "atomize") (Args.mode "full" >> (K o atomize))
"present local premises as object-level statements" #>
setup (Binding.name "rule") (Attrib.thms >> some_rule) "apply some intro/elim rule" #>
setup (Binding.name "erule") (xrule_meth erule) "apply rule in elimination manner (improper)" #>
setup (Binding.name "drule") (xrule_meth drule) "apply rule in destruct manner (improper)" #>
setup (Binding.name "frule") (xrule_meth frule) "apply rule in forward manner (improper)" #>
setup (Binding.name "this") (Scan.succeed (K this)) "apply current facts as rules" #>
setup (Binding.name "fact") (Attrib.thms >> fact) "composition by facts from context" #>
setup (Binding.name "assumption") (Scan.succeed assumption)
"proof by assumption, preferring facts" #>
setup (Binding.name "rename_tac") (Args.goal_spec -- Scan.lift (Scan.repeat1 Args.name) >>
(fn (quant, xs) => K (SIMPLE_METHOD'' quant (Tactic.rename_tac xs))))
"rename parameters of goal" #>
setup (Binding.name "rotate_tac") (Args.goal_spec -- Scan.lift (Scan.optional Parse.int 1) >>
(fn (quant, i) => K (SIMPLE_METHOD'' quant (Tactic.rotate_tac i))))
"rotate assumptions of goal" #>
setup (Binding.name "tactic") (Scan.lift Args.name_source_position >> tactic)
"ML tactic as proof method" #>
setup (Binding.name "raw_tactic") (Scan.lift Args.name_source_position >> raw_tactic)
"ML tactic as raw proof method"));
(*final declarations of this structure!*)
val unfold = unfold_meth;
val fold = fold_meth;
end;
structure Basic_Method: BASIC_METHOD = Method;
open Basic_Method;
val RAW_METHOD_CASES = Method.RAW_METHOD_CASES;
val RAW_METHOD = Method.RAW_METHOD;
val METHOD_CASES = Method.METHOD_CASES;
val METHOD = Method.METHOD;
val SIMPLE_METHOD = Method.SIMPLE_METHOD;
val SIMPLE_METHOD' = Method.SIMPLE_METHOD';
val SIMPLE_METHOD'' = Method.SIMPLE_METHOD'';