krauss@20270: 
krauss@19564: (*  Title:      HOL/Tools/function_package/fundef_package.ML
krauss@19564:     ID:         $Id$
krauss@19564:     Author:     Alexander Krauss, TU Muenchen
krauss@19564: 
krauss@19564: A package for general recursive function definitions. 
krauss@19564: Isar commands.
krauss@19564: 
krauss@19564: *)
krauss@19564: 
krauss@19564: signature FUNDEF_PACKAGE = 
krauss@19564: sig
krauss@20270:     val add_fundef : ((bstring * (Attrib.src list * bool)) * string) list list -> bool -> theory -> Proof.state (* Need an _i variant *)
krauss@19564: 
krauss@19564:     val cong_add: attribute
krauss@19564:     val cong_del: attribute
krauss@19564: 							 
krauss@19564:     val setup : theory -> theory
krauss@19770:     val get_congs : theory -> thm list
krauss@19564: end
krauss@19564: 
krauss@19564: 
krauss@19564: structure FundefPackage : FUNDEF_PACKAGE =
krauss@19564: struct
krauss@19564: 
krauss@19564: open FundefCommon
krauss@19564: 
krauss@19564: 
krauss@20270: fun add_simps label moreatts (MutualPart {f_name, ...}, psimps) spec_part thy =
krauss@19770:     let 
krauss@20270:       val psimpss = Library.unflat (map snd spec_part) psimps
krauss@20270:       val (names, attss) = split_list (map fst spec_part) 
krauss@20270: 
krauss@19770:       val thy = thy |> Theory.add_path f_name 
krauss@19770:                 
krauss@19770:       val thy = thy |> Theory.add_path label
krauss@20270:       val spsimpss = map (map standard) psimpss (* FIXME *)
krauss@20270:       val add_list = (names ~~ spsimpss) ~~ attss
krauss@20270:       val (_, thy) = PureThy.add_thmss add_list thy
krauss@19770:       val thy = thy |> Theory.parent_path
krauss@19770:                 
krauss@20270:       val (_, thy) = PureThy.add_thmss [((label, flat spsimpss), Simplifier.simp_add :: moreatts)] thy
krauss@19770:       val thy = thy |> Theory.parent_path
krauss@19770:     in
krauss@19770:       thy
krauss@19770:     end
krauss@19770:     
krauss@19770: 
krauss@19770: 
krauss@19770: 
krauss@19770: 
krauss@19770: 
krauss@20270: fun fundef_afterqed congs mutual_info name data spec [[result]] thy =
krauss@19564:     let
krauss@19922: 	val fundef_data = FundefMutual.mk_partial_rules_mutual thy mutual_info data result
krauss@19922: 	val FundefMResult {psimps, subset_pinducts, simple_pinducts, termination, domintros, cases, ...} = fundef_data
krauss@19922:         val Mutual {parts, ...} = mutual_info
krauss@19564: 
krauss@19583: 	val Prep {names = Names {acc_R=accR, ...}, ...} = data
krauss@19583: 	val dom_abbrev = Logic.mk_equals (Free (name ^ "_dom", fastype_of accR), accR)
krauss@19583: 	val (_, thy) = LocalTheory.mapping NONE (Specification.abbreviation_i ("", false) [(NONE, dom_abbrev)]) thy
krauss@19564: 
krauss@20270:         val thy = fold2 (add_simps "psimps" []) (parts ~~ psimps) spec thy
krauss@20270: 
krauss@20270:         val casenames = flat (map (map (fst o fst)) spec)
krauss@19564: 
krauss@19770: 	val thy = thy |> Theory.add_path name
krauss@20270: 	val (_, thy) = PureThy.add_thms [(("cases", cases), [RuleCases.case_names casenames])] thy
krauss@19770: 	val (_, thy) = PureThy.add_thmss [(("domintros", domintros), [])] thy
krauss@19922: 	val (_, thy) = PureThy.add_thms [(("termination", standard termination), [])] thy
krauss@20270: 	val (_,thy) = PureThy.add_thmss [(("pinduct", map standard simple_pinducts), [RuleCases.case_names casenames, InductAttrib.induct_set ""])] thy
krauss@19564: 	val thy = thy |> Theory.parent_path
krauss@19564:     in
krauss@20270:       add_fundef_data name (fundef_data, mutual_info, spec) thy
krauss@19564:     end
krauss@19564: 
krauss@20285: fun gen_add_fundef prep_att eqns_attss (preprocess : bool) thy =
krauss@19564:     let
krauss@20270:       fun prep_eqns neqs =
krauss@20270:           neqs
krauss@20270:             |> map (apsnd (Sign.read_prop thy))    
krauss@20270:             |> map (apfst (apsnd (apfst (map (prep_att thy)))))
krauss@20270:             |> FundefSplit.split_some_equations (ProofContext.init thy)
krauss@20270:       
krauss@20270:       val spec = map prep_eqns eqns_attss
krauss@20270:       val t_eqnss = map (flat o map snd) spec
krauss@19770: 
krauss@20270: (*
krauss@20270:  val t_eqns = if preprocess then map (FundefSplit.split_all_equations (ProofContext.init thy)) t_eqns
krauss@20270:               else t_eqns
krauss@20270: *)
krauss@19564: 
krauss@20270:       val congs = get_fundef_congs (Context.Theory thy)
krauss@19564: 
krauss@20270:       val (mutual_info, name, (data, thy)) = FundefMutual.prepare_fundef_mutual congs t_eqnss thy
krauss@20270:       val Prep {goal, goalI, ...} = data
krauss@19564:     in
krauss@19564: 	thy |> ProofContext.init
krauss@20270: 	    |> Proof.theorem_i PureThy.internalK NONE (fundef_afterqed congs mutual_info name data spec) NONE ("", [])
krauss@19922: 	    [(("", []), [(goal, [])])]
krauss@19922:             |> Proof.refine (Method.primitive_text (fn _ => goalI))
krauss@19922:             |> Seq.hd
krauss@19564:     end
krauss@19564: 
krauss@19564: 
krauss@19770: fun total_termination_afterqed name (Mutual {parts, ...}) thmss thy =
krauss@19564:     let
krauss@19564: 	val totality = hd (hd thmss)
krauss@19564: 
krauss@20270: 	val (FundefMResult {psimps, simple_pinducts, ... }, Mutual {parts, ...}, spec)
krauss@19564: 	  = the (get_fundef_data name thy)
krauss@19564: 
wenzelm@20320: 	val remove_domain_condition = full_simplify (HOL_basic_ss addsimps [totality, True_implies_equals])
krauss@19564: 
krauss@19770: 	val tsimps = map (map remove_domain_condition) psimps
krauss@19770: 	val tinduct = map remove_domain_condition simple_pinducts
krauss@19770: 
krauss@19784:         val has_guards = exists ((fn (Const ("Trueprop", _) $ _) => false | _ => true) o prop_of) (flat tsimps)
krauss@19784:         val allatts = if has_guards then [] else [RecfunCodegen.add NONE]
krauss@19784: 
krauss@20270:         val thy = fold2 (add_simps "simps" allatts) (parts ~~ tsimps) spec thy
krauss@19564: 
krauss@19564: 	val thy = Theory.add_path name thy
krauss@19564: 		  
krauss@19770: 	val (_, thy) = PureThy.add_thmss [(("induct", map standard tinduct), [])] thy 
krauss@19564: 	val thy = Theory.parent_path thy
krauss@19564:     in
krauss@19564: 	thy
krauss@19564:     end
krauss@19564: 
krauss@19564: (*
krauss@19564: fun mk_partial_rules name D_name D domT idomT thmss thy =
krauss@19564:     let
krauss@19564: 	val [subs, dcl] = (hd thmss)
krauss@19564: 
krauss@19564: 	val {f_const, f_curried_const, G_const, R_const, G_elims, completeness, f_simps, names_attrs, subset_induct, ... }
krauss@19564: 	  = the (Symtab.lookup (FundefData.get thy) name)
krauss@19564: 
krauss@19564: 	val D_implies_dom = subs COMP (instantiate' [SOME (ctyp_of thy idomT)] 
krauss@19564: 						    [SOME (cterm_of thy D)]
krauss@19564: 						    subsetD)
krauss@19564: 
krauss@19564: 	val D_simps = map (curry op RS D_implies_dom) f_simps
krauss@19564: 
krauss@19564: 	val D_induct = subset_induct
krauss@19564: 			   |> cterm_instantiate [(cterm_of thy (Var (("D",0), fastype_of D)) ,cterm_of thy D)]
krauss@19564: 			   |> curry op COMP subs
krauss@19564: 			   |> curry op COMP (dcl |> forall_intr (cterm_of thy (Var (("z",0), idomT)))
krauss@19564: 						 |> forall_intr (cterm_of thy (Var (("x",0), idomT))))
krauss@19564: 
krauss@19564: 	val ([tinduct'], thy2) = PureThy.add_thms [((name ^ "_" ^ D_name ^ "_induct", D_induct), [])] thy
krauss@19564: 	val ([tsimps'], thy3) = PureThy.add_thmss [((name ^ "_" ^ D_name ^ "_simps", D_simps), [])] thy2
krauss@19564:     in
krauss@19564: 	thy3
krauss@19564:     end
krauss@19564: *)
krauss@19564:  
krauss@19564: 
krauss@19564: fun fundef_setup_termination_proof name NONE thy = 
krauss@19564:     let
krauss@19564: 	val name = if name = "" then get_last_fundef thy else name
krauss@19564: 	val data = the (get_fundef_data name thy)
krauss@19938:                    handle Option.Option => raise ERROR ("No such function definition: " ^ name)
krauss@19564: 
krauss@20270: 	val (res as FundefMResult {termination, ...}, mutual, _) = data
krauss@19564: 	val goal = FundefTermination.mk_total_termination_goal data
krauss@19564:     in
krauss@19564: 	thy |> ProofContext.init
krauss@19770: 	    |> ProofContext.note_thmss_i [(("termination", 
krauss@19922: 					    [ContextRules.intro_query NONE]), [([standard termination], [])])] |> snd
krauss@19770: 	    |> Proof.theorem_i PureThy.internalK NONE (total_termination_afterqed name mutual) NONE ("", [])
wenzelm@19585: 	    [(("", []), [(goal, [])])]
krauss@19564:     end	
krauss@19564:   | fundef_setup_termination_proof name (SOME (dom_name, dom)) thy =
krauss@19564:     let
krauss@19564: 	val name = if name = "" then get_last_fundef thy else name
krauss@19564: 	val data = the (get_fundef_data name thy)
krauss@19564: 	val (subs, dcl) = FundefTermination.mk_partial_termination_goal thy data dom
krauss@19564:     in
krauss@19564: 	thy |> ProofContext.init
krauss@19564: 	    |> Proof.theorem_i PureThy.internalK NONE (K I) NONE ("", [])
wenzelm@19585: 	    [(("", []), [(subs, []), (dcl, [])])]
krauss@19564:     end	
krauss@19564: 
krauss@19564: 
krauss@19611: val add_fundef = gen_add_fundef Attrib.attribute
krauss@19611: 
krauss@19564: 
krauss@19564: 
krauss@19564: (* congruence rules *)
krauss@19564: 
wenzelm@19617: val cong_add = Thm.declaration_attribute (map_fundef_congs o Drule.add_rule o safe_mk_meta_eq);
wenzelm@19617: val cong_del = Thm.declaration_attribute (map_fundef_congs o Drule.del_rule o safe_mk_meta_eq);
krauss@19564: 
krauss@19564: 
krauss@19564: (* setup *)
krauss@19564: 
krauss@19564: val setup = FundefData.init #> FundefCongs.init 
krauss@19564: 	#>  Attrib.add_attributes
krauss@19564: 		[("fundef_cong", Attrib.add_del_args cong_add cong_del, "declaration of congruence rule for function definitions")]
krauss@19564: 
krauss@19564: 
krauss@19770: val get_congs = FundefCommon.get_fundef_congs o Context.Theory
krauss@19770: 
krauss@19770: 
krauss@19564: (* outer syntax *)
krauss@19564: 
krauss@19564: local structure P = OuterParse and K = OuterKeyword in
krauss@19564: 
krauss@20270: 
krauss@20270: 
krauss@20270: val star = Scan.one (fn t => (OuterLex.val_of t = "*"));
krauss@20270: 
krauss@20270: 
krauss@20270: val attribs_with_star = P.$$$ "[" |-- P.!!! ((P.list (star >> K NONE || P.attrib >> SOME)) 
krauss@20270:                                                >> (fn x => (map_filter I x, exists is_none x)))
krauss@20270:                               --| P.$$$ "]";
krauss@20270: 
krauss@20270: val opt_attribs_with_star = Scan.optional attribs_with_star ([], false);
krauss@20270: 
krauss@20270: fun opt_thm_name_star s =
krauss@20270:   Scan.optional ((P.name -- opt_attribs_with_star || (attribs_with_star >> pair "")) --| P.$$$ s) ("", ([], false));
krauss@20270: 
krauss@20270: 
krauss@19564: val function_decl =
krauss@20270:     Scan.repeat1 (opt_thm_name_star ":" -- P.prop);
krauss@19564: 
krauss@19564: val functionP =
krauss@19564:   OuterSyntax.command "function" "define general recursive functions" K.thy_goal
krauss@20270:   (((Scan.optional (P.$$$ "(" -- P.!!! (P.$$$ "pre" -- P.$$$ ")") >> K true) false) --    
krauss@20270:   P.and_list1 function_decl) >> (fn (prepr, eqnss) =>
krauss@20270:                                     Toplevel.print o Toplevel.theory_to_proof (add_fundef eqnss prepr)));
krauss@19564: 
krauss@19564: val terminationP =
krauss@19564:   OuterSyntax.command "termination" "prove termination of a recursive function" K.thy_goal
krauss@19564:   ((Scan.optional P.name "" -- Scan.option (P.$$$ "(" |-- Scan.optional (P.name --| P.$$$ ":") "dom" -- P.term --| P.$$$ ")"))
krauss@19564:        >> (fn (name,dom) =>
krauss@19564: 	      Toplevel.print o Toplevel.theory_to_proof (fundef_setup_termination_proof name dom)));
krauss@19564: 
krauss@19564: val _ = OuterSyntax.add_parsers [functionP];
krauss@19564: val _ = OuterSyntax.add_parsers [terminationP];
krauss@19564: 
krauss@19564: 
krauss@19564: end;
krauss@19564: 
krauss@19564: 
wenzelm@19585: end