(* Title: HOL/Tools/Quotient/quotient_tacs.thy
Author: Cezary Kaliszyk and Christian Urban
Tactics for solving goal arising from lifting theorems to quotient
types.
*)
signature QUOTIENT_TACS =
sig
val regularize_tac: Proof.context -> int -> tactic
val injection_tac: Proof.context -> int -> tactic
val all_injection_tac: Proof.context -> int -> tactic
val clean_tac: Proof.context -> int -> tactic
val procedure_tac: Proof.context -> thm -> int -> tactic
val lift_tac: Proof.context -> thm list -> int -> tactic
val quotient_tac: Proof.context -> int -> tactic
val quot_true_tac: Proof.context -> (term -> term) -> int -> tactic
val lifted: typ list -> Proof.context -> thm -> thm
val lifted_attrib: attribute
end;
structure Quotient_Tacs: QUOTIENT_TACS =
struct
open Quotient_Info;
open Quotient_Term;
(** various helper fuctions **)
(* Since HOL_basic_ss is too "big" for us, we *)
(* need to set up our own minimal simpset. *)
fun mk_minimal_ss ctxt =
Simplifier.context ctxt empty_ss
setsubgoaler asm_simp_tac
setmksimps (mksimps [])
(* composition of two theorems, used in maps *)
fun OF1 thm1 thm2 = thm2 RS thm1
fun atomize_thm thm =
let
val thm' = Thm.legacy_freezeT (forall_intr_vars thm) (* FIXME/TODO: is this proper Isar-technology? *)
val thm'' = Object_Logic.atomize (cprop_of thm')
in
@{thm equal_elim_rule1} OF [thm'', thm']
end
(*** Regularize Tactic ***)
(** solvers for equivp and quotient assumptions **)
fun equiv_tac ctxt =
REPEAT_ALL_NEW (resolve_tac (equiv_rules_get ctxt))
fun equiv_solver_tac ss = equiv_tac (Simplifier.the_context ss)
val equiv_solver = Simplifier.mk_solver' "Equivalence goal solver" equiv_solver_tac
fun quotient_tac ctxt =
(REPEAT_ALL_NEW (FIRST'
[rtac @{thm identity_quotient},
resolve_tac (quotient_rules_get ctxt)]))
fun quotient_solver_tac ss = quotient_tac (Simplifier.the_context ss)
val quotient_solver =
Simplifier.mk_solver' "Quotient goal solver" quotient_solver_tac
fun solve_quotient_assm ctxt thm =
case Seq.pull (quotient_tac ctxt 1 thm) of
SOME (t, _) => t
| _ => error "Solve_quotient_assm failed. Possibly a quotient theorem is missing."
fun prep_trm thy (x, (T, t)) =
(cterm_of thy (Var (x, T)), cterm_of thy t)
fun prep_ty thy (x, (S, ty)) =
(ctyp_of thy (TVar (x, S)), ctyp_of thy ty)
fun get_match_inst thy pat trm =
let
val univ = Unify.matchers thy [(pat, trm)]
val SOME (env, _) = Seq.pull univ (* raises Bind, if no unifier *) (* FIXME fragile *)
val tenv = Vartab.dest (Envir.term_env env)
val tyenv = Vartab.dest (Envir.type_env env)
in
(map (prep_ty thy) tyenv, map (prep_trm thy) tenv)
end
(* Calculates the instantiations for the lemmas:
ball_reg_eqv_range and bex_reg_eqv_range
Since the left-hand-side contains a non-pattern '?P (f ?x)'
we rely on unification/instantiation to check whether the
theorem applies and return NONE if it doesn't.
*)
fun calculate_inst ctxt ball_bex_thm redex R1 R2 =
let
val thy = ProofContext.theory_of ctxt
fun get_lhs thm = fst (Logic.dest_equals (Thm.concl_of thm))
val ty_inst = map (SOME o ctyp_of thy) [domain_type (fastype_of R2)]
val trm_inst = map (SOME o cterm_of thy) [R2, R1]
in
case try (Drule.instantiate' ty_inst trm_inst) ball_bex_thm of
NONE => NONE
| SOME thm' =>
(case try (get_match_inst thy (get_lhs thm')) redex of
NONE => NONE
| SOME inst2 => try (Drule.instantiate inst2) thm')
end
fun ball_bex_range_simproc ss redex =
let
val ctxt = Simplifier.the_context ss
in
case redex of
(Const (@{const_name "Ball"}, _) $ (Const (@{const_name "Respects"}, _) $
(Const (@{const_name "fun_rel"}, _) $ R1 $ R2)) $ _) =>
calculate_inst ctxt @{thm ball_reg_eqv_range[THEN eq_reflection]} redex R1 R2
| (Const (@{const_name "Bex"}, _) $ (Const (@{const_name "Respects"}, _) $
(Const (@{const_name "fun_rel"}, _) $ R1 $ R2)) $ _) =>
calculate_inst ctxt @{thm bex_reg_eqv_range[THEN eq_reflection]} redex R1 R2
| _ => NONE
end
(* Regularize works as follows:
0. preliminary simplification step according to
ball_reg_eqv bex_reg_eqv babs_reg_eqv ball_reg_eqv_range bex_reg_eqv_range
1. eliminating simple Ball/Bex instances (ball_reg_right bex_reg_left)
2. monos
3. commutation rules for ball and bex (ball_all_comm bex_ex_comm)
4. then rel-equalities, which need to be instantiated with 'eq_imp_rel'
to avoid loops
5. then simplification like 0
finally jump back to 1
*)
fun reflp_get ctxt =
map_filter (fn th => if prems_of th = [] then SOME (OF1 @{thm equivp_reflp} th) else NONE
handle THM _ => NONE) (equiv_rules_get ctxt)
val eq_imp_rel = @{lemma "equivp R ==> a = b --> R a b" by (simp add: equivp_reflp)}
fun eq_imp_rel_get ctxt = map (OF1 eq_imp_rel) (equiv_rules_get ctxt)
fun regularize_tac ctxt =
let
val thy = ProofContext.theory_of ctxt
val ball_pat = @{term "Ball (Respects (R1 ===> R2)) P"}
val bex_pat = @{term "Bex (Respects (R1 ===> R2)) P"}
val simproc = Simplifier.simproc_i thy "" [ball_pat, bex_pat] (K (ball_bex_range_simproc))
val simpset = (mk_minimal_ss ctxt)
addsimps @{thms ball_reg_eqv bex_reg_eqv babs_reg_eqv babs_simp}
addsimprocs [simproc]
addSolver equiv_solver addSolver quotient_solver
val eq_eqvs = eq_imp_rel_get ctxt
in
simp_tac simpset THEN'
REPEAT_ALL_NEW (CHANGED o FIRST'
[resolve_tac @{thms ball_reg_right bex_reg_left bex1_bexeq_reg},
resolve_tac (Inductive.get_monos ctxt),
resolve_tac @{thms ball_all_comm bex_ex_comm},
resolve_tac eq_eqvs,
simp_tac simpset])
end
(*** Injection Tactic ***)
(* Looks for Quot_True assumptions, and in case its parameter
is an application, it returns the function and the argument.
*)
fun find_qt_asm asms =
let
fun find_fun trm =
case trm of
(Const(@{const_name Trueprop}, _) $ (Const (@{const_name Quot_True}, _) $ _)) => true
| _ => false
in
case find_first find_fun asms of
SOME (_ $ (_ $ (f $ a))) => SOME (f, a)
| _ => NONE
end
fun quot_true_simple_conv ctxt fnctn ctrm =
case (term_of ctrm) of
(Const (@{const_name Quot_True}, _) $ x) =>
let
val fx = fnctn x;
val thy = ProofContext.theory_of ctxt;
val cx = cterm_of thy x;
val cfx = cterm_of thy fx;
val cxt = ctyp_of thy (fastype_of x);
val cfxt = ctyp_of thy (fastype_of fx);
val thm = Drule.instantiate' [SOME cxt, SOME cfxt] [SOME cx, SOME cfx] @{thm QT_imp}
in
Conv.rewr_conv thm ctrm
end
fun quot_true_conv ctxt fnctn ctrm =
case (term_of ctrm) of
(Const (@{const_name Quot_True}, _) $ _) =>
quot_true_simple_conv ctxt fnctn ctrm
| _ $ _ => Conv.comb_conv (quot_true_conv ctxt fnctn) ctrm
| Abs _ => Conv.abs_conv (fn (_, ctxt) => quot_true_conv ctxt fnctn) ctxt ctrm
| _ => Conv.all_conv ctrm
fun quot_true_tac ctxt fnctn =
CONVERSION
((Conv.params_conv ~1 (fn ctxt =>
(Conv.prems_conv ~1 (quot_true_conv ctxt fnctn)))) ctxt)
fun dest_comb (f $ a) = (f, a)
fun dest_bcomb ((_ $ l) $ r) = (l, r)
fun unlam t =
case t of
(Abs a) => snd (Term.dest_abs a)
| _ => unlam (Abs("", domain_type (fastype_of t), (incr_boundvars 1 t) $ (Bound 0)))
fun dest_fun_type (Type("fun", [T, S])) = (T, S)
| dest_fun_type _ = error "dest_fun_type"
val bare_concl = HOLogic.dest_Trueprop o Logic.strip_assums_concl
(* We apply apply_rsp only in case if the type needs lifting.
This is the case if the type of the data in the Quot_True
assumption is different from the corresponding type in the goal.
*)
val apply_rsp_tac =
Subgoal.FOCUS (fn {concl, asms, context,...} =>
let
val bare_concl = HOLogic.dest_Trueprop (term_of concl)
val qt_asm = find_qt_asm (map term_of asms)
in
case (bare_concl, qt_asm) of
(R2 $ (f $ x) $ (g $ y), SOME (qt_fun, qt_arg)) =>
if fastype_of qt_fun = fastype_of f
then no_tac
else
let
val ty_x = fastype_of x
val ty_b = fastype_of qt_arg
val ty_f = range_type (fastype_of f)
val thy = ProofContext.theory_of context
val ty_inst = map (SOME o (ctyp_of thy)) [ty_x, ty_b, ty_f]
val t_inst = map (SOME o (cterm_of thy)) [R2, f, g, x, y];
val inst_thm = Drule.instantiate' ty_inst
([NONE, NONE, NONE] @ t_inst) @{thm apply_rsp}
in
(rtac inst_thm THEN' SOLVED' (quotient_tac context)) 1
end
| _ => no_tac
end)
(* Instantiates and applies 'equals_rsp'. Since the theorem is
complex we rely on instantiation to tell us if it applies
*)
fun equals_rsp_tac R ctxt =
let
val thy = ProofContext.theory_of ctxt
in
case try (cterm_of thy) R of (* There can be loose bounds in R *)
SOME ctm =>
let
val ty = domain_type (fastype_of R)
in
case try (Drule.instantiate' [SOME (ctyp_of thy ty)]
[SOME (cterm_of thy R)]) @{thm equals_rsp} of
SOME thm => rtac thm THEN' quotient_tac ctxt
| NONE => K no_tac
end
| _ => K no_tac
end
fun rep_abs_rsp_tac ctxt =
SUBGOAL (fn (goal, i) =>
case (try bare_concl goal) of
SOME (rel $ _ $ (rep $ (Bound _ $ _))) => no_tac
| SOME (rel $ _ $ (rep $ (abs $ _))) =>
let
val thy = ProofContext.theory_of ctxt;
val (ty_a, ty_b) = dest_fun_type (fastype_of abs);
val ty_inst = map (SOME o (ctyp_of thy)) [ty_a, ty_b];
in
case try (map (SOME o (cterm_of thy))) [rel, abs, rep] of
SOME t_inst =>
(case try (Drule.instantiate' ty_inst t_inst) @{thm rep_abs_rsp} of
SOME inst_thm => (rtac inst_thm THEN' quotient_tac ctxt) i
| NONE => no_tac)
| NONE => no_tac
end
| _ => no_tac)
(* Injection means to prove that the regularised theorem implies
the abs/rep injected one.
The deterministic part:
- remove lambdas from both sides
- prove Ball/Bex/Babs equalities using ball_rsp, bex_rsp, babs_rsp
- prove Ball/Bex relations unfolding fun_rel_id
- reflexivity of equality
- prove equality of relations using equals_rsp
- use user-supplied RSP theorems
- solve 'relation of relations' goals using quot_rel_rsp
- remove rep_abs from the right side
(Lambdas under respects may have left us some assumptions)
Then in order:
- split applications of lifted type (apply_rsp)
- split applications of non-lifted type (cong_tac)
- apply extentionality
- assumption
- reflexivity of the relation
*)
fun injection_match_tac ctxt = SUBGOAL (fn (goal, i) =>
(case (bare_concl goal) of
(* (R1 ===> R2) (%x...) (%x...) ----> [|R1 x y|] ==> R2 (...x) (...y) *)
(Const (@{const_name fun_rel}, _) $ _ $ _) $ (Abs _) $ (Abs _)
=> rtac @{thm fun_rel_id} THEN' quot_true_tac ctxt unlam
(* (op =) (Ball...) (Ball...) ----> (op =) (...) (...) *)
| (Const (@{const_name "op ="},_) $
(Const(@{const_name Ball},_) $ (Const (@{const_name Respects}, _) $ _) $ _) $
(Const(@{const_name Ball},_) $ (Const (@{const_name Respects}, _) $ _) $ _))
=> rtac @{thm ball_rsp} THEN' dtac @{thm QT_all}
(* (R1 ===> op =) (Ball...) (Ball...) ----> [|R1 x y|] ==> (Ball...x) = (Ball...y) *)
| (Const (@{const_name fun_rel}, _) $ _ $ _) $
(Const(@{const_name Ball},_) $ (Const (@{const_name Respects}, _) $ _) $ _) $
(Const(@{const_name Ball},_) $ (Const (@{const_name Respects}, _) $ _) $ _)
=> rtac @{thm fun_rel_id} THEN' quot_true_tac ctxt unlam
(* (op =) (Bex...) (Bex...) ----> (op =) (...) (...) *)
| Const (@{const_name "op ="},_) $
(Const(@{const_name Bex},_) $ (Const (@{const_name Respects}, _) $ _) $ _) $
(Const(@{const_name Bex},_) $ (Const (@{const_name Respects}, _) $ _) $ _)
=> rtac @{thm bex_rsp} THEN' dtac @{thm QT_ex}
(* (R1 ===> op =) (Bex...) (Bex...) ----> [|R1 x y|] ==> (Bex...x) = (Bex...y) *)
| (Const (@{const_name fun_rel}, _) $ _ $ _) $
(Const(@{const_name Bex},_) $ (Const (@{const_name Respects}, _) $ _) $ _) $
(Const(@{const_name Bex},_) $ (Const (@{const_name Respects}, _) $ _) $ _)
=> rtac @{thm fun_rel_id} THEN' quot_true_tac ctxt unlam
| (Const (@{const_name fun_rel}, _) $ _ $ _) $
(Const(@{const_name Bex1_rel},_) $ _) $ (Const(@{const_name Bex1_rel},_) $ _)
=> rtac @{thm bex1_rel_rsp} THEN' quotient_tac ctxt
| (_ $
(Const(@{const_name Babs},_) $ (Const (@{const_name Respects}, _) $ _) $ _) $
(Const(@{const_name Babs},_) $ (Const (@{const_name Respects}, _) $ _) $ _))
=> rtac @{thm babs_rsp} THEN' RANGE [quotient_tac ctxt]
| Const (@{const_name "op ="},_) $ (R $ _ $ _) $ (_ $ _ $ _) =>
(rtac @{thm refl} ORELSE'
(equals_rsp_tac R ctxt THEN' RANGE [
quot_true_tac ctxt (fst o dest_bcomb), quot_true_tac ctxt (snd o dest_bcomb)]))
(* reflexivity of operators arising from Cong_tac *)
| Const (@{const_name "op ="},_) $ _ $ _ => rtac @{thm refl}
(* respectfulness of constants; in particular of a simple relation *)
| _ $ (Const _) $ (Const _) (* fun_rel, list_rel, etc but not equality *)
=> resolve_tac (rsp_rules_get ctxt) THEN_ALL_NEW quotient_tac ctxt
(* R (...) (Rep (Abs ...)) ----> R (...) (...) *)
(* observe fun_map *)
| _ $ _ $ _
=> (rtac @{thm quot_rel_rsp} THEN_ALL_NEW quotient_tac ctxt)
ORELSE' rep_abs_rsp_tac ctxt
| _ => K no_tac
) i)
fun injection_step_tac ctxt rel_refl =
FIRST' [
injection_match_tac ctxt,
(* R (t $ ...) (t' $ ...) ----> apply_rsp provided type of t needs lifting *)
apply_rsp_tac ctxt THEN'
RANGE [quot_true_tac ctxt (fst o dest_comb), quot_true_tac ctxt (snd o dest_comb)],
(* (op =) (t $ ...) (t' $ ...) ----> Cong provided type of t does not need lifting *)
(* merge with previous tactic *)
Cong_Tac.cong_tac @{thm cong} THEN'
RANGE [quot_true_tac ctxt (fst o dest_comb), quot_true_tac ctxt (snd o dest_comb)],
(* (op =) (%x...) (%y...) ----> (op =) (...) (...) *)
rtac @{thm ext} THEN' quot_true_tac ctxt unlam,
(* resolving with R x y assumptions *)
atac,
(* reflexivity of the basic relations *)
(* R ... ... *)
resolve_tac rel_refl]
fun injection_tac ctxt =
let
val rel_refl = reflp_get ctxt
in
injection_step_tac ctxt rel_refl
end
fun all_injection_tac ctxt =
REPEAT_ALL_NEW (injection_tac ctxt)
(*** Cleaning of the Theorem ***)
(* expands all fun_maps, except in front of the (bound) variables listed in xs *)
fun fun_map_simple_conv xs ctrm =
case (term_of ctrm) of
((Const (@{const_name "fun_map"}, _) $ _ $ _) $ h $ _) =>
if member (op=) xs h
then Conv.all_conv ctrm
else Conv.rewr_conv @{thm fun_map_def[THEN eq_reflection]} ctrm
| _ => Conv.all_conv ctrm
fun fun_map_conv xs ctxt ctrm =
case (term_of ctrm) of
_ $ _ => (Conv.comb_conv (fun_map_conv xs ctxt) then_conv
fun_map_simple_conv xs) ctrm
| Abs _ => Conv.abs_conv (fn (x, ctxt) => fun_map_conv ((term_of x)::xs) ctxt) ctxt ctrm
| _ => Conv.all_conv ctrm
fun fun_map_tac ctxt = CONVERSION (fun_map_conv [] ctxt)
(* custom matching functions *)
fun mk_abs u i t =
if incr_boundvars i u aconv t then Bound i else
case t of
t1 $ t2 => mk_abs u i t1 $ mk_abs u i t2
| Abs (s, T, t') => Abs (s, T, mk_abs u (i + 1) t')
| Bound j => if i = j then error "make_inst" else t
| _ => t
fun make_inst lhs t =
let
val _ $ (Abs (_, _, (_ $ ((f as Var (_, Type ("fun", [T, _]))) $ u)))) = lhs;
val _ $ (Abs (_, _, (_ $ g))) = t;
in
(f, Abs ("x", T, mk_abs u 0 g))
end
fun make_inst_id lhs t =
let
val _ $ (Abs (_, _, (f as Var (_, Type ("fun", [T, _]))) $ u)) = lhs;
val _ $ (Abs (_, _, g)) = t;
in
(f, Abs ("x", T, mk_abs u 0 g))
end
(* Simplifies a redex using the 'lambda_prs' theorem.
First instantiates the types and known subterms.
Then solves the quotient assumptions to get Rep2 and Abs1
Finally instantiates the function f using make_inst
If Rep2 is an identity then the pattern is simpler and
make_inst_id is used
*)
fun lambda_prs_simple_conv ctxt ctrm =
case (term_of ctrm) of
(Const (@{const_name fun_map}, _) $ r1 $ a2) $ (Abs _) =>
let
val thy = ProofContext.theory_of ctxt
val (ty_b, ty_a) = dest_fun_type (fastype_of r1)
val (ty_c, ty_d) = dest_fun_type (fastype_of a2)
val tyinst = map (SOME o (ctyp_of thy)) [ty_a, ty_b, ty_c, ty_d]
val tinst = [NONE, NONE, SOME (cterm_of thy r1), NONE, SOME (cterm_of thy a2)]
val thm1 = Drule.instantiate' tyinst tinst @{thm lambda_prs[THEN eq_reflection]}
val thm2 = solve_quotient_assm ctxt (solve_quotient_assm ctxt thm1)
val thm3 = MetaSimplifier.rewrite_rule @{thms id_apply[THEN eq_reflection]} thm2
val (insp, inst) =
if ty_c = ty_d
then make_inst_id (term_of (Thm.lhs_of thm3)) (term_of ctrm)
else make_inst (term_of (Thm.lhs_of thm3)) (term_of ctrm)
val thm4 = Drule.instantiate ([], [(cterm_of thy insp, cterm_of thy inst)]) thm3
in
Conv.rewr_conv thm4 ctrm
end
| _ => Conv.all_conv ctrm
fun lambda_prs_conv ctxt = Conv.top_conv lambda_prs_simple_conv ctxt
fun lambda_prs_tac ctxt = CONVERSION (lambda_prs_conv ctxt)
(* Cleaning consists of:
1. unfolding of ---> in front of everything, except
bound variables (this prevents lambda_prs from
becoming stuck)
2. simplification with lambda_prs
3. simplification with:
- Quotient_abs_rep Quotient_rel_rep
babs_prs all_prs ex_prs ex1_prs
- id_simps and preservation lemmas and
- symmetric versions of the definitions
(that is definitions of quotient constants
are folded)
4. test for refl
*)
fun clean_tac lthy =
let
val defs = map (Thm.symmetric o #def) (qconsts_dest lthy)
val prs = prs_rules_get lthy
val ids = id_simps_get lthy
val thms = @{thms Quotient_abs_rep Quotient_rel_rep babs_prs all_prs ex_prs ex1_prs} @ ids @ prs @ defs
val ss = (mk_minimal_ss lthy) addsimps thms addSolver quotient_solver
in
EVERY' [fun_map_tac lthy,
lambda_prs_tac lthy,
simp_tac ss,
TRY o rtac refl]
end
(** Tactic for Generalising Free Variables in a Goal **)
fun inst_spec ctrm =
Drule.instantiate' [SOME (ctyp_of_term ctrm)] [NONE, SOME ctrm] @{thm spec}
fun inst_spec_tac ctrms =
EVERY' (map (dtac o inst_spec) ctrms)
fun all_list xs trm =
fold (fn (x, T) => fn t' => HOLogic.mk_all (x, T, t')) xs trm
fun apply_under_Trueprop f =
HOLogic.dest_Trueprop #> f #> HOLogic.mk_Trueprop
fun gen_frees_tac ctxt =
SUBGOAL (fn (concl, i) =>
let
val thy = ProofContext.theory_of ctxt
val vrs = Term.add_frees concl []
val cvrs = map (cterm_of thy o Free) vrs
val concl' = apply_under_Trueprop (all_list vrs) concl
val goal = Logic.mk_implies (concl', concl)
val rule = Goal.prove ctxt [] [] goal
(K (EVERY1 [inst_spec_tac (rev cvrs), atac]))
in
rtac rule i
end)
(** The General Shape of the Lifting Procedure **)
(* - A is the original raw theorem
- B is the regularized theorem
- C is the rep/abs injected version of B
- D is the lifted theorem
- 1st prem is the regularization step
- 2nd prem is the rep/abs injection step
- 3rd prem is the cleaning part
the Quot_True premise in 2nd records the lifted theorem
*)
val lifting_procedure_thm =
@{lemma "[|A;
A --> B;
Quot_True D ==> B = C;
C = D|] ==> D"
by (simp add: Quot_True_def)}
fun lift_match_error ctxt msg rtrm qtrm =
let
val rtrm_str = Syntax.string_of_term ctxt rtrm
val qtrm_str = Syntax.string_of_term ctxt qtrm
val msg = cat_lines [enclose "[" "]" msg, "The quotient theorem", qtrm_str,
"", "does not match with original theorem", rtrm_str]
in
error msg
end
fun procedure_inst ctxt rtrm qtrm =
let
val thy = ProofContext.theory_of ctxt
val rtrm' = HOLogic.dest_Trueprop rtrm
val qtrm' = HOLogic.dest_Trueprop qtrm
val reg_goal = regularize_trm_chk ctxt (rtrm', qtrm')
handle (LIFT_MATCH msg) => lift_match_error ctxt msg rtrm qtrm
val inj_goal = inj_repabs_trm_chk ctxt (reg_goal, qtrm')
handle (LIFT_MATCH msg) => lift_match_error ctxt msg rtrm qtrm
in
Drule.instantiate' []
[SOME (cterm_of thy rtrm'),
SOME (cterm_of thy reg_goal),
NONE,
SOME (cterm_of thy inj_goal)] lifting_procedure_thm
end
(* the tactic leaves three subgoals to be proved *)
fun procedure_tac ctxt rthm =
Object_Logic.full_atomize_tac
THEN' gen_frees_tac ctxt
THEN' SUBGOAL (fn (goal, i) =>
let
val rthm' = atomize_thm rthm
val rule = procedure_inst ctxt (prop_of rthm') goal
in
(rtac rule THEN' rtac rthm') i
end)
(* Automatic Proofs *)
fun lift_tac ctxt rthms =
let
fun mk_tac rthm =
procedure_tac ctxt rthm
THEN' RANGE
[regularize_tac ctxt,
all_injection_tac ctxt,
clean_tac ctxt]
in
simp_tac (mk_minimal_ss ctxt) (* unfolding multiple &&& *)
THEN' RANGE (map mk_tac rthms)
end
fun lifted qtys ctxt thm =
let
(* When the theorem is atomized, eta redexes are contracted,
so we do it both in the original theorem *)
val thm' = Drule.eta_contraction_rule thm
val ((_, [thm'']), ctxt') = Variable.import false [thm'] ctxt
val goal = (quotient_lift_all qtys ctxt' o prop_of) thm''
in
Goal.prove ctxt' [] [] goal (K (lift_tac ctxt' [thm'] 1))
|> singleton (ProofContext.export ctxt' ctxt)
end;
(* An Attribute which automatically constructs the qthm *)
val lifted_attrib = Thm.rule_attribute (fn ctxt => lifted [] (Context.proof_of ctxt))
end; (* structure *)