theory QuotMain
imports QuotScript QuotList Prove
uses ("quotient.ML")
begin
locale QUOT_TYPE =
fixes R :: "'a \<Rightarrow> 'a \<Rightarrow> bool"
and Abs :: "('a \<Rightarrow> bool) \<Rightarrow> 'b"
and Rep :: "'b \<Rightarrow> ('a \<Rightarrow> bool)"
assumes equiv: "EQUIV R"
and rep_prop: "\<And>y. \<exists>x. Rep y = R x"
and rep_inverse: "\<And>x. Abs (Rep x) = x"
and abs_inverse: "\<And>x. (Rep (Abs (R x))) = (R x)"
and rep_inject: "\<And>x y. (Rep x = Rep y) = (x = y)"
begin
definition
ABS::"'a \<Rightarrow> 'b"
where
"ABS x \<equiv> Abs (R x)"
definition
REP::"'b \<Rightarrow> 'a"
where
"REP a = Eps (Rep a)"
lemma lem9:
shows "R (Eps (R x)) = R x"
proof -
have a: "R x x" using equiv by (simp add: EQUIV_REFL_SYM_TRANS REFL_def)
then have "R x (Eps (R x))" by (rule someI)
then show "R (Eps (R x)) = R x"
using equiv unfolding EQUIV_def by simp
qed
theorem thm10:
shows "ABS (REP a) \<equiv> a"
apply (rule eq_reflection)
unfolding ABS_def REP_def
proof -
from rep_prop
obtain x where eq: "Rep a = R x" by auto
have "Abs (R (Eps (Rep a))) = Abs (R (Eps (R x)))" using eq by simp
also have "\<dots> = Abs (R x)" using lem9 by simp
also have "\<dots> = Abs (Rep a)" using eq by simp
also have "\<dots> = a" using rep_inverse by simp
finally
show "Abs (R (Eps (Rep a))) = a" by simp
qed
lemma REP_refl:
shows "R (REP a) (REP a)"
unfolding REP_def
by (simp add: equiv[simplified EQUIV_def])
lemma lem7:
shows "(R x = R y) = (Abs (R x) = Abs (R y))"
apply(rule iffI)
apply(simp)
apply(drule rep_inject[THEN iffD2])
apply(simp add: abs_inverse)
done
theorem thm11:
shows "R r r' = (ABS r = ABS r')"
unfolding ABS_def
by (simp only: equiv[simplified EQUIV_def] lem7)
lemma REP_ABS_rsp:
shows "R f (REP (ABS g)) = R f g"
and "R (REP (ABS g)) f = R g f"
by (simp_all add: thm10 thm11)
lemma QUOTIENT:
"QUOTIENT R ABS REP"
apply(unfold QUOTIENT_def)
apply(simp add: thm10)
apply(simp add: REP_refl)
apply(subst thm11[symmetric])
apply(simp add: equiv[simplified EQUIV_def])
done
lemma R_trans:
assumes ab: "R a b"
and bc: "R b c"
shows "R a c"
proof -
have tr: "TRANS R" using equiv EQUIV_REFL_SYM_TRANS[of R] by simp
moreover have ab: "R a b" by fact
moreover have bc: "R b c" by fact
ultimately show "R a c" unfolding TRANS_def by blast
qed
lemma R_sym:
assumes ab: "R a b"
shows "R b a"
proof -
have re: "SYM R" using equiv EQUIV_REFL_SYM_TRANS[of R] by simp
then show "R b a" using ab unfolding SYM_def by blast
qed
lemma R_trans2:
assumes ac: "R a c"
and bd: "R b d"
shows "R a b = R c d"
using ac bd
by (blast intro: R_trans R_sym)
lemma REPS_same:
shows "R (REP a) (REP b) \<equiv> (a = b)"
proof -
have "R (REP a) (REP b) = (a = b)"
proof
assume as: "R (REP a) (REP b)"
from rep_prop
obtain x y
where eqs: "Rep a = R x" "Rep b = R y" by blast
from eqs have "R (Eps (R x)) (Eps (R y))" using as unfolding REP_def by simp
then have "R x (Eps (R y))" using lem9 by simp
then have "R (Eps (R y)) x" using R_sym by blast
then have "R y x" using lem9 by simp
then have "R x y" using R_sym by blast
then have "ABS x = ABS y" using thm11 by simp
then have "Abs (Rep a) = Abs (Rep b)" using eqs unfolding ABS_def by simp
then show "a = b" using rep_inverse by simp
next
assume ab: "a = b"
have "REFL R" using equiv EQUIV_REFL_SYM_TRANS[of R] by simp
then show "R (REP a) (REP b)" unfolding REFL_def using ab by auto
qed
then show "R (REP a) (REP b) \<equiv> (a = b)" by simp
qed
end
section {* type definition for the quotient type *}
use "quotient.ML"
declare [[map list = (map, LIST_REL)]]
declare [[map * = (prod_fun, prod_rel)]]
declare [[map "fun" = (fun_map, FUN_REL)]]
ML {* maps_lookup @{theory} "List.list" *}
ML {* maps_lookup @{theory} "*" *}
ML {* maps_lookup @{theory} "fun" *}
text {* FIXME: auxiliary function *}
ML {*
val no_vars = Thm.rule_attribute (fn context => fn th =>
let
val ctxt = Variable.set_body false (Context.proof_of context);
val ((_, [th']), _) = Variable.import true [th] ctxt;
in th' end);
*}
section {* lifting of constants *}
ML {*
(* whether ty1 is an instance of ty2 *)
fun matches (ty1, ty2) =
Type.raw_instance (ty1, Logic.varifyT ty2)
fun lookup_snd _ [] _ = NONE
| lookup_snd eq ((value, key)::xs) key' =
if eq (key', key) then SOME value
else lookup_snd eq xs key';
fun lookup_qenv qenv qty =
(case (AList.lookup matches qenv qty) of
SOME rty => SOME (qty, rty)
| NONE => NONE)
*}
ML {*
(* calculates the aggregate abs and rep functions for a given type;
repF is for constants' arguments; absF is for constants;
function types need to be treated specially, since repF and absF
change
*)
datatype flag = absF | repF
fun negF absF = repF
| negF repF = absF
fun get_fun flag qenv lthy ty =
let
fun get_fun_aux s fs_tys =
let
val (fs, tys) = split_list fs_tys
val (otys, ntys) = split_list tys
val oty = Type (s, otys)
val nty = Type (s, ntys)
val ftys = map (op -->) tys
in
(case (maps_lookup (ProofContext.theory_of lthy) s) of
SOME info => (list_comb (Const (#mapfun info, ftys ---> (oty --> nty)), fs), (oty, nty))
| NONE => raise ERROR ("no map association for type " ^ s))
end
fun get_fun_fun fs_tys =
let
val (fs, tys) = split_list fs_tys
val ([oty1, oty2], [nty1, nty2]) = split_list tys
val oty = nty1 --> oty2
val nty = oty1 --> nty2
val ftys = map (op -->) tys
in
(list_comb (Const (@{const_name "fun_map"}, ftys ---> oty --> nty), fs), (oty, nty))
end
fun get_const flag (qty, rty) =
let
val thy = ProofContext.theory_of lthy
val qty_name = Long_Name.base_name (fst (dest_Type qty))
in
case flag of
absF => (Const (Sign.full_bname thy ("ABS_" ^ qty_name), rty --> qty), (rty, qty))
| repF => (Const (Sign.full_bname thy ("REP_" ^ qty_name), qty --> rty), (qty, rty))
end
fun mk_identity ty = Abs ("", ty, Bound 0)
in
if (AList.defined matches qenv ty)
then (get_const flag (the (lookup_qenv qenv ty)))
else (case ty of
TFree _ => (mk_identity ty, (ty, ty))
| Type (_, []) => (mk_identity ty, (ty, ty))
| Type ("fun" , [ty1, ty2]) =>
get_fun_fun [get_fun (negF flag) qenv lthy ty1, get_fun flag qenv lthy ty2]
| Type (s, tys) => get_fun_aux s (map (get_fun flag qenv lthy) tys)
| _ => raise ERROR ("no type variables")
)
end
*}
text {* produces the definition for a lifted constant *}
ML {*
fun get_const_def nconst otrm qenv lthy =
let
val ty = fastype_of nconst
val (arg_tys, res_ty) = strip_type ty
val rep_fns = map (fst o get_fun repF qenv lthy) arg_tys
val abs_fn = (fst o get_fun absF qenv lthy) res_ty
fun mk_fun_map (t1,t2) = Const (@{const_name "fun_map"}, dummyT) $ t1 $ t2
val fns = Library.foldr mk_fun_map (rep_fns, abs_fn)
|> Syntax.check_term lthy
in
fns $ otrm
end
*}
ML {* lookup_snd *}
ML {*
fun exchange_ty qenv ty =
case (lookup_snd matches qenv ty) of
SOME qty => qty
| NONE =>
(case ty of
Type (s, tys) => Type (s, map (exchange_ty qenv) tys)
| _ => ty
)
*}
ML {*
fun make_const_def nconst_bname otrm mx qenv lthy =
let
val otrm_ty = fastype_of otrm
val nconst_ty = exchange_ty qenv otrm_ty
val nconst = Const (Binding.name_of nconst_bname, nconst_ty)
val def_trm = get_const_def nconst otrm qenv lthy
in
define (nconst_bname, mx, def_trm) lthy
end
*}
ML {*
fun build_qenv lthy qtys =
let
val qenv = map (fn {qtyp, rtyp, ...} => (qtyp, rtyp)) (quotdata_lookup lthy)
fun find_assoc qty =
case (AList.lookup matches qenv qty) of
SOME rty => (qty, rty)
| NONE => error (implode
["Quotient type ",
quote (Syntax.string_of_typ lthy qty),
" does not exists"])
in
map find_assoc qtys
end
*}
ML {*
(* taken from isar_syn.ML *)
val constdecl =
OuterParse.binding --
(OuterParse.where_ >> K (NONE, NoSyn) ||
OuterParse.$$$ "::" |-- OuterParse.!!! ((OuterParse.typ >> SOME) --
OuterParse.opt_mixfix' --| OuterParse.where_) ||
Scan.ahead (OuterParse.$$$ "(") |--
OuterParse.!!! (OuterParse.mixfix' --| OuterParse.where_ >> pair NONE))
*}
ML {*
val qd_parser =
(Args.parens (OuterParse.$$$ "for" |-- (Scan.repeat OuterParse.typ))) --
(constdecl -- (SpecParse.opt_thm_name ":" -- OuterParse.prop))
*}
ML {*
fun pair lthy (ty1, ty2) =
"(" ^ (Syntax.string_of_typ lthy ty1) ^ "," ^ (Syntax.string_of_typ lthy ty2) ^ ")"
*}
ML {*
fun parse_qd_spec (qtystrs, ((bind, (typstr__, mx)), (attr__, propstr))) lthy =
let
val qtys = map (Syntax.check_typ lthy o Syntax.parse_typ lthy) qtystrs
val qenv = build_qenv lthy qtys
val prop = Syntax.parse_prop lthy propstr |> Syntax.check_prop lthy
val (lhs, rhs) = Logic.dest_equals prop
in
make_const_def bind rhs mx qenv lthy |> snd
end
*}
ML {*
val _ = OuterSyntax.local_theory "quotient_def" "lifted definition of constants"
OuterKeyword.thy_decl (qd_parser >> parse_qd_spec)
*}
section {* ATOMIZE *}
text {*
Unabs_def converts a definition given as
c \<equiv> %x. %y. f x y
to a theorem of the form
c x y \<equiv> f x y
This function is needed to rewrite the right-hand
side to the left-hand side.
*}
ML {*
fun unabs_def ctxt def =
let
val (lhs, rhs) = Thm.dest_equals (cprop_of def)
val xs = strip_abs_vars (term_of rhs)
val (_, ctxt') = Variable.add_fixes (map fst xs) ctxt
val thy = ProofContext.theory_of ctxt'
val cxs = map (cterm_of thy o Free) xs
val new_lhs = Drule.list_comb (lhs, cxs)
fun get_conv [] = Conv.rewr_conv def
| get_conv (x::xs) = Conv.fun_conv (get_conv xs)
in
get_conv xs new_lhs |>
singleton (ProofContext.export ctxt' ctxt)
end
*}
lemma atomize_eqv[atomize]:
shows "(Trueprop A \<equiv> Trueprop B) \<equiv> (A \<equiv> B)"
proof
assume "A \<equiv> B"
then show "Trueprop A \<equiv> Trueprop B" by unfold
next
assume *: "Trueprop A \<equiv> Trueprop B"
have "A = B"
proof (cases A)
case True
have "A" by fact
then show "A = B" using * by simp
next
case False
have "\<not>A" by fact
then show "A = B" using * by auto
qed
then show "A \<equiv> B" by (rule eq_reflection)
qed
ML {*
fun atomize_thm thm =
let
val thm' = Thm.freezeT (forall_intr_vars thm)
val thm'' = ObjectLogic.atomize (cprop_of thm')
in
@{thm Pure.equal_elim_rule1} OF [thm'', thm']
end
*}
ML {* atomize_thm @{thm list.induct} *}
section {* REGULARIZE *}
text {* tyRel takes a type and builds a relation that a quantifier over this
type needs to respect. *}
ML {*
fun tyRel ty rty rel lthy =
if ty = rty
then rel
else (case ty of
Type (s, tys) =>
let
val tys_rel = map (fn ty => ty --> ty --> @{typ bool}) tys;
val ty_out = ty --> ty --> @{typ bool};
val tys_out = tys_rel ---> ty_out;
in
(case (maps_lookup (ProofContext.theory_of lthy) s) of
SOME (info) => list_comb (Const (#relfun info, tys_out), map (fn ty => tyRel ty rty rel lthy) tys)
| NONE => HOLogic.eq_const ty
)
end
| _ => HOLogic.eq_const ty)
*}
definition
Babs :: "('a \<Rightarrow> bool) \<Rightarrow> ('a \<Rightarrow> 'b) \<Rightarrow> 'a \<Rightarrow> 'b"
where
"(x \<in> p) \<Longrightarrow> (Babs p m x = m x)"
(* TODO: Consider defining it with an "if"; sth like:
Babs p m = \<lambda>x. if x \<in> p then m x else undefined
*)
ML {*
fun needs_lift (rty as Type (rty_s, _)) ty =
case ty of
Type (s, tys) =>
(s = rty_s) orelse (exists (needs_lift rty) tys)
| _ => false
*}
ML {*
(* trm \<Rightarrow> new_trm *)
fun regularise trm rty rel lthy =
case trm of
Abs (x, T, t) =>
if (needs_lift rty T) then let
val ([x'], lthy2) = Variable.variant_fixes [x] lthy;
val v = Free (x', T);
val t' = subst_bound (v, t);
val rec_term = regularise t' rty rel lthy2;
val lam_term = Term.lambda_name (x, v) rec_term;
val sub_res_term = tyRel T rty rel lthy;
val respects = Const (@{const_name Respects}, (fastype_of sub_res_term) --> T --> @{typ bool});
val res_term = respects $ sub_res_term;
val ty = fastype_of trm;
val rabs = Const (@{const_name Babs}, (fastype_of res_term) --> ty --> ty);
val rabs_term = (rabs $ res_term) $ lam_term;
in
rabs_term
end else let
val ([x'], lthy2) = Variable.variant_fixes [x] lthy;
val v = Free (x', T);
val t' = subst_bound (v, t);
val rec_term = regularise t' rty rel lthy2;
in
Term.lambda_name (x, v) rec_term
end
| ((Const (@{const_name "All"}, at)) $ (Abs (x, T, t))) =>
if (needs_lift rty T) then let
val ([x'], lthy2) = Variable.variant_fixes [x] lthy;
val v = Free (x', T);
val t' = subst_bound (v, t);
val rec_term = regularise t' rty rel lthy2;
val lam_term = Term.lambda_name (x, v) rec_term;
val sub_res_term = tyRel T rty rel lthy;
val respects = Const (@{const_name Respects}, (fastype_of sub_res_term) --> T --> @{typ bool});
val res_term = respects $ sub_res_term;
val ty = fastype_of lam_term;
val rall = Const (@{const_name Ball}, (fastype_of res_term) --> ty --> @{typ bool});
val rall_term = (rall $ res_term) $ lam_term;
in
rall_term
end else let
val ([x'], lthy2) = Variable.variant_fixes [x] lthy;
val v = Free (x', T);
val t' = subst_bound (v, t);
val rec_term = regularise t' rty rel lthy2;
val lam_term = Term.lambda_name (x, v) rec_term
in
Const(@{const_name "All"}, at) $ lam_term
end
| ((Const (@{const_name "All"}, at)) $ P) =>
let
val (_, [al, _]) = dest_Type (fastype_of P);
val ([x], lthy2) = Variable.variant_fixes [""] lthy;
val v = (Free (x, al));
val abs = Term.lambda_name (x, v) (P $ v);
in regularise ((Const (@{const_name "All"}, at)) $ abs) rty rel lthy2 end
| ((Const (@{const_name "Ex"}, at)) $ (Abs (x, T, t))) =>
if (needs_lift rty T) then let
val ([x'], lthy2) = Variable.variant_fixes [x] lthy;
val v = Free (x', T);
val t' = subst_bound (v, t);
val rec_term = regularise t' rty rel lthy2;
val lam_term = Term.lambda_name (x, v) rec_term;
val sub_res_term = tyRel T rty rel lthy;
val respects = Const (@{const_name Respects}, (fastype_of sub_res_term) --> T --> @{typ bool});
val res_term = respects $ sub_res_term;
val ty = fastype_of lam_term;
val rall = Const (@{const_name Bex}, (fastype_of res_term) --> ty --> @{typ bool});
val rall_term = (rall $ res_term) $ lam_term;
in
rall_term
end else let
val ([x'], lthy2) = Variable.variant_fixes [x] lthy;
val v = Free (x', T);
val t' = subst_bound (v, t);
val rec_term = regularise t' rty rel lthy2;
val lam_term = Term.lambda_name (x, v) rec_term
in
Const(@{const_name "Ex"}, at) $ lam_term
end
| ((Const (@{const_name "Ex"}, at)) $ P) =>
let
val (_, [al, _]) = dest_Type (fastype_of P);
val ([x], lthy2) = Variable.variant_fixes [""] lthy;
val v = (Free (x, al));
val abs = Term.lambda_name (x, v) (P $ v);
in regularise ((Const (@{const_name "Ex"}, at)) $ abs) rty rel lthy2 end
| a $ b => (regularise a rty rel lthy) $ (regularise b rty rel lthy)
| _ => trm
*}
(* my version of regularise *)
(****************************)
(* some helper functions *)
ML {*
fun mk_babs ty ty' = Const (@{const_name "Babs"}, [ty' --> @{typ bool}, ty] ---> ty)
fun mk_ball ty = Const (@{const_name "Ball"}, [ty, ty] ---> @{typ bool})
fun mk_bex ty = Const (@{const_name "Bex"}, [ty, ty] ---> @{typ bool})
fun mk_resp ty = Const (@{const_name Respects}, [[ty, ty] ---> @{typ bool}, ty] ---> @{typ bool})
*}
(* applies f to the subterm of an abstractions, otherwise to the given term *)
ML {*
fun apply_subt f trm =
case trm of
Abs (x, T, t) =>
let
val (x', t') = Term.dest_abs (x, T, t)
in
Term.absfree (x', T, f t')
end
| _ => f trm
*}
(* FIXME: assumes always the typ is qty! *)
(* FIXME: if there are more than one quotient, then you have to look up the relation *)
ML {*
fun my_reg rel trm =
case trm of
Abs (x, T, t) =>
let
val ty1 = fastype_of trm
in
(mk_babs ty1 T) $ (mk_resp T $ rel) $ (apply_subt (my_reg rel) trm)
end
| Const (@{const_name "All"}, ty) $ t =>
let
val ty1 = domain_type ty
val ty2 = domain_type ty1
in
(mk_ball ty1) $ (mk_resp ty2 $ rel) $ (apply_subt (my_reg rel) t)
end
| Const (@{const_name "Ex"}, ty) $ t =>
let
val ty1 = domain_type ty
val ty2 = domain_type ty1
in
(mk_bex ty1) $ (mk_resp ty2 $ rel) $ (apply_subt (my_reg rel) t)
end
| t1 $ t2 => (my_reg rel t1) $ (my_reg rel t2)
| _ => trm
*}
(*fun prove_reg trm \<Rightarrow> thm (we might need some facts to do this)
trm == new_trm
*)
text {* Assumes that the given theorem is atomized *}
ML {*
fun build_regularize_goal thm rty rel lthy =
Logic.mk_implies
((prop_of thm),
(regularise (prop_of thm) rty rel lthy))
*}
ML {*
fun regularize thm rty rel rel_eqv lthy =
let
val g = build_regularize_goal thm rty rel lthy;
fun tac ctxt =
(asm_full_simp_tac ((Simplifier.context ctxt HOL_ss) addsimps
[(@{thm equiv_res_forall} OF [rel_eqv]),
(@{thm equiv_res_exists} OF [rel_eqv])])) THEN_ALL_NEW
(((rtac @{thm RIGHT_RES_FORALL_REGULAR}) THEN' (RANGE [fn _ => all_tac, atac]) THEN'
(MetisTools.metis_tac ctxt [])) ORELSE' (MetisTools.metis_tac ctxt []));
val cthm = Goal.prove lthy [] [] g (fn x => tac (#context x) 1);
in
cthm OF [thm]
end
*}
section {* RepAbs injection *}
(* Needed to have a meta-equality *)
lemma id_def_sym: "(\<lambda>x. x) \<equiv> id"
by (simp add: id_def)
ML {*
fun old_exchange_ty rty qty ty =
if ty = rty
then qty
else
(case ty of
Type (s, tys) => Type (s, map (old_exchange_ty rty qty) tys)
| _ => ty
)
*}
ML {*
fun old_get_fun flag rty qty lthy ty =
get_fun flag [(qty, rty)] lthy ty
fun old_make_const_def nconst_bname otrm mx rty qty lthy =
make_const_def nconst_bname otrm mx [(qty, rty)] lthy
*}
ML {*
fun build_repabs_term lthy thm constructors rty qty =
let
fun mk_rep tm =
let
val ty = old_exchange_ty rty qty (fastype_of tm)
in fst (old_get_fun repF rty qty lthy ty) $ tm end
fun mk_abs tm =
let
val ty = old_exchange_ty rty qty (fastype_of tm) in
fst (old_get_fun absF rty qty lthy ty) $ tm end
fun is_constructor (Const (x, _)) = member (op =) constructors x
| is_constructor _ = false;
fun build_aux lthy tm =
case tm of
Abs (a as (_, vty, _)) =>
let
val (vs, t) = Term.dest_abs a;
val v = Free(vs, vty);
val t' = lambda v (build_aux lthy t)
in
if (not (needs_lift rty (fastype_of tm))) then t'
else mk_rep (mk_abs (
if not (needs_lift rty vty) then t'
else
let
val v' = mk_rep (mk_abs v);
val t1 = Envir.beta_norm (t' $ v')
in
lambda v t1
end
))
end
| x =>
let
val (opp, tms0) = Term.strip_comb tm
val tms = map (build_aux lthy) tms0
val ty = fastype_of tm
in
if (((fst (Term.dest_Const opp)) = @{const_name Respects}) handle _ => false)
then (list_comb (opp, (hd tms0) :: (tl tms)))
else if (is_constructor opp andalso needs_lift rty ty) then
mk_rep (mk_abs (list_comb (opp,tms)))
else if ((Term.is_Free opp) andalso (length tms > 0) andalso (needs_lift rty ty)) then
mk_rep(mk_abs(list_comb(opp,tms)))
else if tms = [] then opp
else list_comb(opp, tms)
end
in
MetaSimplifier.rewrite_term @{theory} @{thms id_def_sym} []
(build_aux lthy (Thm.prop_of thm))
end
*}
text {* Assumes that it is given a regularized theorem *}
ML {*
fun build_repabs_goal ctxt thm cons rty qty =
Logic.mk_equals ((Thm.prop_of thm), (build_repabs_term ctxt thm cons rty qty))
*}
ML {*
fun instantiate_tac thm = Subgoal.FOCUS (fn {concl, ...} =>
let
val pat = Drule.strip_imp_concl (cprop_of thm)
val insts = Thm.match (pat, concl)
in
rtac (Drule.instantiate insts thm) 1
end
handle _ => no_tac
)
*}
ML {*
fun res_forall_rsp_tac ctxt =
(simp_tac ((Simplifier.context ctxt HOL_ss) addsimps @{thms FUN_REL.simps}))
THEN' rtac @{thm allI} THEN' rtac @{thm allI} THEN' rtac @{thm impI}
THEN' instantiate_tac @{thm RES_FORALL_RSP} ctxt THEN'
(simp_tac ((Simplifier.context ctxt HOL_ss) addsimps @{thms FUN_REL.simps}))
*}
ML {*
fun res_exists_rsp_tac ctxt =
(simp_tac ((Simplifier.context ctxt HOL_ss) addsimps @{thms FUN_REL.simps}))
THEN' rtac @{thm allI} THEN' rtac @{thm allI} THEN' rtac @{thm impI}
THEN' instantiate_tac @{thm RES_EXISTS_RSP} ctxt THEN'
(simp_tac ((Simplifier.context ctxt HOL_ss) addsimps @{thms FUN_REL.simps}))
*}
ML {*
fun quotient_tac quot_thm =
REPEAT_ALL_NEW (FIRST' [
rtac @{thm FUN_QUOTIENT},
rtac quot_thm,
rtac @{thm IDENTITY_QUOTIENT}
])
*}
ML {*
fun LAMBDA_RES_TAC ctxt i st =
(case (term_of o #concl o fst) (Subgoal.focus ctxt i st) of
(_ $ (_ $ (Abs(_,_,_))$(Abs(_,_,_)))) =>
(EqSubst.eqsubst_tac ctxt [0] @{thms FUN_REL.simps}) THEN'
(rtac @{thm allI}) THEN' (rtac @{thm allI}) THEN' (rtac @{thm impI})
| _ => fn _ => no_tac) i st
*}
ML {*
fun WEAK_LAMBDA_RES_TAC ctxt i st =
(case (term_of o #concl o fst) (Subgoal.focus ctxt i st) of
(_ $ (_ $ _$(Abs(_,_,_)))) =>
(EqSubst.eqsubst_tac ctxt [0] @{thms FUN_REL.simps}) THEN'
(rtac @{thm allI}) THEN' (rtac @{thm allI}) THEN' (rtac @{thm impI})
| (_ $ (_ $ (Abs(_,_,_))$_)) =>
(EqSubst.eqsubst_tac ctxt [0] @{thms FUN_REL.simps}) THEN'
(rtac @{thm allI}) THEN' (rtac @{thm allI}) THEN' (rtac @{thm impI})
| _ => fn _ => no_tac) i st
*}
ML {*
fun APPLY_RSP_TAC rty = Subgoal.FOCUS (fn {concl, ...} =>
let
val (_ $ (R $ (f $ _) $ (_ $ _))) = term_of concl;
val pat = Drule.strip_imp_concl (cprop_of @{thm APPLY_RSP});
val insts = Thm.match (pat, concl)
in
if needs_lift rty (type_of f) then
rtac (Drule.instantiate insts @{thm APPLY_RSP}) 1
else no_tac
end
handle _ => no_tac)
*}
ML {*
fun r_mk_comb_tac ctxt rty quot_thm reflex_thm trans_thm rsp_thms =
(FIRST' [
rtac @{thm FUN_QUOTIENT},
rtac quot_thm,
rtac @{thm IDENTITY_QUOTIENT},
rtac trans_thm,
LAMBDA_RES_TAC ctxt,
res_forall_rsp_tac ctxt,
res_exists_rsp_tac ctxt,
(
(simp_tac ((Simplifier.context ctxt HOL_ss) addsimps rsp_thms))
THEN_ALL_NEW (fn _ => no_tac)
),
(instantiate_tac @{thm REP_ABS_RSP(1)} ctxt THEN' (RANGE [quotient_tac quot_thm])),
rtac refl,
(* rtac @{thm arg_cong2[of _ _ _ _ "op ="]},*)
(APPLY_RSP_TAC rty ctxt THEN' (RANGE [quotient_tac quot_thm, quotient_tac quot_thm])),
Cong_Tac.cong_tac @{thm cong},
rtac @{thm ext},
rtac reflex_thm,
atac,
(
(simp_tac ((Simplifier.context ctxt HOL_ss) addsimps @{thms FUN_REL.simps}))
THEN_ALL_NEW (fn _ => no_tac)
),
WEAK_LAMBDA_RES_TAC ctxt
])
*}
ML {*
fun repabs lthy thm constructors rty qty quot_thm reflex_thm trans_thm rsp_thms =
let
val rt = build_repabs_term lthy thm constructors rty qty;
val rg = Logic.mk_equals ((Thm.prop_of thm), rt);
fun tac ctxt = (ObjectLogic.full_atomize_tac) THEN'
(REPEAT_ALL_NEW (r_mk_comb_tac ctxt rty quot_thm reflex_thm trans_thm rsp_thms));
val cthm = Goal.prove lthy [] [] rg (fn x => tac (#context x) 1);
in
@{thm Pure.equal_elim_rule1} OF [cthm, thm]
end
*}
section {* Cleaning the goal *}
text {* Does the same as 'subst' in a given theorem *}
ML {*
fun eqsubst_thm ctxt thms thm =
let
val goalstate = Goal.init (Thm.cprop_of thm)
val a' = case (SINGLE (EqSubst.eqsubst_tac ctxt [0] thms 1) goalstate) of
NONE => error "eqsubst_thm"
| SOME th => cprem_of th 1
val tac = (EqSubst.eqsubst_tac ctxt [0] thms 1) THEN simp_tac HOL_ss 1
val cgoal = cterm_of (ProofContext.theory_of ctxt) (Logic.mk_equals (term_of (Thm.cprop_of thm), term_of a'))
val rt = Toplevel.program (fn () => Goal.prove_internal [] cgoal (fn _ => tac));
in
@{thm Pure.equal_elim_rule1} OF [rt,thm]
end
*}
ML {*
fun repeat_eqsubst_thm ctxt thms thm =
repeat_eqsubst_thm ctxt thms (eqsubst_thm ctxt thms thm)
handle _ => thm
*}
text {* expects atomized definition *}
ML {*
fun add_lower_defs_aux ctxt thm =
let
val e1 = @{thm fun_cong} OF [thm];
val f = eqsubst_thm ctxt @{thms fun_map.simps} e1;
val g = MetaSimplifier.rewrite_rule @{thms id_def_sym} f;
val h = repeat_eqsubst_thm ctxt @{thms FUN_MAP_I} g;
val i = MetaSimplifier.rewrite_rule [@{thm eq_reflection} OF @{thms id_apply}] h
in
thm :: (add_lower_defs_aux ctxt i)
end
handle _ => [thm]
*}
ML {*
fun add_lower_defs ctxt defs =
let
val defs_pre_sym = map symmetric defs
val defs_atom = map atomize_thm defs_pre_sym
val defs_all = flat (map (add_lower_defs_aux ctxt) defs_atom)
in
map Thm.varifyT defs_all
end
*}
text {* the proper way to do it *}
ML {*
fun findabs rty tm =
case tm of
Abs(_, T, b) =>
let
val b' = subst_bound ((Free ("x", T)), b);
val tys = findabs rty b'
val ty = fastype_of tm
in if needs_lift rty ty then (ty :: tys) else tys
end
| f $ a => (findabs rty f) @ (findabs rty a)
| _ => []
*}
ML {*
fun make_simp_lam_prs_thm lthy quot_thm typ =
let
val (_, [lty, rty]) = dest_Type typ;
val thy = ProofContext.theory_of lthy;
val (lcty, rcty) = (ctyp_of thy lty, ctyp_of thy rty)
val inst = [SOME lcty, NONE, SOME rcty];
val lpi = Drule.instantiate' inst [] @{thm LAMBDA_PRS};
val tac =
(compose_tac (false, @{thm LAMBDA_PRS}, 2)) THEN_ALL_NEW
(quotient_tac quot_thm);
val t = Goal.prove lthy [] [] (concl_of lpi) (fn _ => tac 1);
val ts = @{thm HOL.sym} OF [t]
in
MetaSimplifier.rewrite_rule [@{thm eq_reflection} OF @{thms id_apply}] ts
end
*}
ML {*
fun simp_allex_prs lthy quot thm =
let
val rwf = @{thm FORALL_PRS} OF [quot];
val rwfs = @{thm "HOL.sym"} OF [rwf];
val rwe = @{thm EXISTS_PRS} OF [quot];
val rwes = @{thm "HOL.sym"} OF [rwe]
in
(simp_allex_prs lthy quot (eqsubst_thm lthy [rwfs, rwes] thm))
end
handle _ => thm
*}
ML {*
fun lift_thm lthy consts rty qty rel rel_eqv rel_refl quot rsp_thms trans2 reps_same t_defs t = let
val t_a = atomize_thm t;
val t_r = regularize t_a rty rel rel_eqv lthy;
val t_t = repabs lthy t_r consts rty qty quot rel_refl trans2 rsp_thms;
val abs = findabs rty (prop_of t_a);
val simp_lam_prs_thms = map (make_simp_lam_prs_thm lthy quot) abs;
val t_l = repeat_eqsubst_thm lthy simp_lam_prs_thms t_t;
val t_a = simp_allex_prs lthy quot t_l;
val t_defs_sym = add_lower_defs lthy t_defs;
val t_d = repeat_eqsubst_thm lthy t_defs_sym t_a;
val t_r = MetaSimplifier.rewrite_rule [reps_same] t_d;
in
ObjectLogic.rulify t_r
end
*}
end