author | haftmann |
Thu, 24 May 2007 08:37:41 +0200 | |
changeset 23088 | a3f11e0ae90f |
parent 23038 | 6ea1dc78807a |
child 23249 | 9ef65be6bb2a |
permissions | -rw-r--r-- |
22023 | 1 |
(* Title: Pure/Tools/codegen_func.ML |
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ID: $Id$ |
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Author: Florian Haftmann, TU Muenchen |
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Basic handling of defining equations ("func"s) for code generator framework. |
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*) |
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signature CODEGEN_FUNC = |
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sig |
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val assert_rew: thm -> thm |
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val mk_rew: thm -> thm |
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val mk_func: thm -> thm |
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val head_func: thm -> CodegenConsts.const * typ |
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val bad_thm: string -> 'a |
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val error_thm: (thm -> thm) -> thm -> thm |
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val warning_thm: (thm -> thm) -> thm -> thm option |
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val inst_thm: sort Vartab.table -> thm -> thm |
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val expand_eta: int -> thm -> thm |
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val rewrite_func: thm list -> thm -> thm |
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val norm_args: thm list -> thm list |
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val norm_varnames: (string -> string) -> (string -> string) -> thm list -> thm list |
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end; |
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structure CodegenFunc : CODEGEN_FUNC = |
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struct |
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(* auxiliary *) |
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exception BAD_THM of string; |
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fun bad_thm msg = raise BAD_THM msg; |
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fun error_thm f thm = f thm handle BAD_THM msg => error msg; |
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fun warning_thm f thm = SOME (f thm) handle BAD_THM msg |
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=> (warning ("code generator: " ^ msg); NONE); |
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(* making rewrite theorems *) |
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fun assert_rew thm = |
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let |
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val thy = Thm.theory_of_thm thm; |
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val (lhs, rhs) = (Logic.dest_equals o Thm.plain_prop_of) thm |
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handle TERM _ => bad_thm ("Not an equation: " ^ Display.string_of_thm thm) |
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handle THM _ => bad_thm ("Not an equation: " ^ Display.string_of_thm thm); |
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fun vars_of t = fold_aterms |
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(fn Var (v, _) => insert (op =) v |
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| Free _ => bad_thm ("Illegal free variable in rewrite theorem\n" |
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^ Display.string_of_thm thm) |
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| _ => I) t []; |
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fun tvars_of t = fold_term_types |
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(fn _ => fold_atyps (fn TVar (v, _) => insert (op =) v |
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| TFree _ => bad_thm |
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("Illegal free type variable in rewrite theorem\n" ^ Display.string_of_thm thm))) t []; |
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val lhs_vs = vars_of lhs; |
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val rhs_vs = vars_of rhs; |
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val lhs_tvs = tvars_of lhs; |
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val rhs_tvs = tvars_of lhs; |
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val _ = if null (subtract (op =) lhs_vs rhs_vs) |
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then () |
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else bad_thm ("Free variables on right hand side of rewrite theorem\n" |
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^ Display.string_of_thm thm); |
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val _ = if null (subtract (op =) lhs_tvs rhs_tvs) |
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then () |
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else bad_thm ("Free type variables on right hand side of rewrite theorem\n" |
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^ Display.string_of_thm thm) |
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in thm end; |
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fun mk_rew thm = |
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let |
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val thy = Thm.theory_of_thm thm; |
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val ctxt = ProofContext.init thy; |
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in |
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thm |
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|> LocalDefs.meta_rewrite_rule ctxt |
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|> assert_rew |
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end; |
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(* making defining equations *) |
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fun assert_func thm = |
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let |
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val thy = Thm.theory_of_thm thm; |
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val (head, args) = (strip_comb o fst o Logic.dest_equals |
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o ObjectLogic.drop_judgment thy o Thm.plain_prop_of) thm; |
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val _ = case head of Const _ => () | _ => |
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bad_thm ("Equation not headed by constant\n" ^ Display.string_of_thm thm); |
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val _ = |
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if has_duplicates (op =) |
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((fold o fold_aterms) (fn Var (v, _) => cons v |
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| _ => I |
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) args []) |
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then bad_thm ("Duplicated variables on left hand side of equation\n" |
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^ Display.string_of_thm thm) |
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else () |
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fun check _ (Abs _) = bad_thm |
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("Abstraction on left hand side of equation\n" |
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^ Display.string_of_thm thm) |
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| check 0 (Var _) = () |
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| check _ (Var _) = bad_thm |
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("Variable with application on left hand side of defining equation\n" |
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^ Display.string_of_thm thm) |
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| check n (t1 $ t2) = (check (n+1) t1; check 0 t2) |
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| check n (Const (_, ty)) = if n <> (length o fst o strip_type) ty |
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then bad_thm |
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("Partially applied constant on left hand side of equation\n" |
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^ Display.string_of_thm thm) |
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else (); |
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val _ = map (check 0) args; |
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in thm end; |
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22484
25dfebd7b4c8
improved treatment of defining equations stemming from specification tools
haftmann
parents:
22475
diff
changeset
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val mk_func = assert_func o mk_rew; |
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fun head_func thm = |
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let |
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val thy = Thm.theory_of_thm thm; |
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val (Const (c_ty as (_, ty))) = (fst o strip_comb o fst o Logic.dest_equals |
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o ObjectLogic.drop_judgment thy o Thm.plain_prop_of) thm; |
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val const = CodegenConsts.const_of_cexpr thy c_ty; |
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in (const, ty) end; |
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(* utilities *) |
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fun inst_thm tvars' thm = |
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let |
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val thy = Thm.theory_of_thm thm; |
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val tvars = (Term.add_tvars o Thm.prop_of) thm []; |
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fun mk_inst (tvar as (v, _)) = case Vartab.lookup tvars' v |
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of SOME sort => SOME (pairself (Thm.ctyp_of thy o TVar) (tvar, (v, sort))) |
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| NONE => NONE; |
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val insts = map_filter mk_inst tvars; |
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in Thm.instantiate (insts, []) thm end; |
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fun expand_eta k thm = |
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let |
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val thy = Thm.theory_of_thm thm; |
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val (lhs, rhs) = (Logic.dest_equals o Thm.plain_prop_of) thm; |
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val (head, args) = strip_comb lhs; |
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val l = if k = ~1 |
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then (length o fst o strip_abs) rhs |
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else Int.max (0, k - length args); |
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val used = Name.make_context (map (fst o fst) (Term.add_vars lhs [])); |
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fun get_name _ 0 used = ([], used) |
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| get_name (Abs (v, ty, t)) k used = |
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used |
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|> Name.variants [v] |
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||>> get_name t (k - 1) |
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|>> (fn ([v'], vs') => (v', ty) :: vs') |
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| get_name t k used = |
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let |
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val (tys, _) = (strip_type o fastype_of) t |
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in case tys |
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of [] => raise TERM ("expand_eta", [t]) |
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| ty :: _ => |
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used |
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|> Name.variants [""] |
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|-> (fn [v] => get_name (t $ Var ((v, 0), ty)) (k - 1) |
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#>> (fn vs' => (v, ty) :: vs')) |
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end; |
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val (vs, _) = get_name rhs l used; |
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val vs_refl = map (fn (v, ty) => Thm.reflexive (Thm.cterm_of thy (Var ((v, 0), ty)))) vs; |
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in |
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thm |
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|> fold (fn refl => fn thm => Thm.combination thm refl) vs_refl |
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|> Conv.fconv_rule Drule.beta_eta_conversion |
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end; |
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fun rewrite_func rewrites thm = |
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let |
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val rewrite = MetaSimplifier.rewrite false rewrites; |
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val (ct_eq, [ct_lhs, ct_rhs]) = (Drule.strip_comb o Thm.cprop_of) thm; |
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val Const ("==", _) = Thm.term_of ct_eq; |
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val (ct_f, ct_args) = Drule.strip_comb ct_lhs; |
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val rhs' = rewrite ct_rhs; |
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val args' = map rewrite ct_args; |
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val lhs' = Thm.symmetric (fold (fn th1 => fn th2 => Thm.combination th2 th1) |
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args' (Thm.reflexive ct_f)); |
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in Thm.transitive (Thm.transitive lhs' thm) rhs' end; |
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fun norm_args thms = |
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let |
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val num_args_of = length o snd o strip_comb o fst o Logic.dest_equals; |
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val k = fold (curry Int.max o num_args_of o Thm.plain_prop_of) thms 0; |
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in |
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thms |
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|> map (expand_eta k) |
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|> map (Conv.fconv_rule Drule.beta_eta_conversion) |
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end; |
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fun canonical_tvars purify_tvar thm = |
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let |
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val ctyp = Thm.ctyp_of (Thm.theory_of_thm thm); |
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fun tvars_subst_for thm = (fold_types o fold_atyps) |
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(fn TVar (v_i as (v, _), sort) => let |
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val v' = purify_tvar v |
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in if v = v' then I |
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else insert (op =) (v_i, (v', sort)) end |
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| _ => I) (prop_of thm) []; |
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fun mk_inst (v_i, (v', sort)) (maxidx, acc) = |
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let |
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val ty = TVar (v_i, sort) |
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in |
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(maxidx + 1, (ctyp ty, ctyp (TVar ((v', maxidx), sort))) :: acc) |
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end; |
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val maxidx = Thm.maxidx_of thm + 1; |
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val (_, inst) = fold mk_inst (tvars_subst_for thm) (maxidx + 1, []); |
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in Thm.instantiate (inst, []) thm end; |
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fun canonical_vars purify_var thm = |
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let |
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val cterm = Thm.cterm_of (Thm.theory_of_thm thm); |
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fun vars_subst_for thm = fold_aterms |
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(fn Var (v_i as (v, _), ty) => let |
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val v' = purify_var v |
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in if v = v' then I |
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else insert (op =) (v_i, (v', ty)) end |
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| _ => I) (prop_of thm) []; |
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fun mk_inst (v_i as (v, i), (v', ty)) (maxidx, acc) = |
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let |
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val t = Var (v_i, ty) |
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in |
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(maxidx + 1, (cterm t, cterm (Var ((v', maxidx), ty))) :: acc) |
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end; |
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val maxidx = Thm.maxidx_of thm + 1; |
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val (_, inst) = fold mk_inst (vars_subst_for thm) (maxidx + 1, []); |
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in Thm.instantiate ([], inst) thm end; |
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fun canonical_absvars purify_var thm = |
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let |
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val t = Thm.plain_prop_of thm; |
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val t' = Term.map_abs_vars purify_var t; |
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in Thm.rename_boundvars t t' thm end; |
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fun norm_varnames purify_tvar purify_var thms = |
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let |
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fun burrow_thms f [] = [] |
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| burrow_thms f thms = |
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thms |
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|> Conjunction.intr_list |
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|> f |
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|> Conjunction.elim_list; |
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in |
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thms |
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|> burrow_thms (canonical_tvars purify_tvar) |
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|> map (canonical_vars purify_var) |
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|> map (canonical_absvars purify_var) |
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|> map Drule.zero_var_indexes |
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end; |
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end; |