# Library Coq.setoid_ring.Ring_tac

Require Import Setoid.
Require Import BinPos.
Require Import Ring_polynom.
Require Import BinList.
Require Import InitialRing.
Require Import Quote.
Ltac compute_assertion eqn t' t :=
let nft := eval vm_compute in t in
pose (t' := nft);
assert (eqn : t = t');
[vm_cast_no_check (refl_equal t')|idtac].
Ltac relation_carrier req :=
let ty := type of req in
match eval hnf in ty with
?R -> _ => R
| _ => fail 1000 "Equality has no relation type"
end.
Ltac Get_goal := match goal with [|- ?G] => G end.
Ltac OnEquation req :=
match goal with
| |- req ?lhs ?rhs => (fun f => f lhs rhs)
| _ => (fun _ => fail "Goal is not an equation (of expected equality)")
end.
Ltac OnEquationHyp req h :=
match type of h with
| req ?lhs ?rhs => fun f => f lhs rhs
| _ => (fun _ => fail "Hypothesis is not an equation (of expected equality)")
end.
Ltac OnMainSubgoal H ty :=
match ty with
| _ -> ?ty' =>
let subtac := OnMainSubgoal H ty' in
fun kont => lapply H; [clear H; intro H; subtac kont | idtac]
| _ => (fun kont => kont())
end.
Ltac ProveLemmaHyp lemma :=
match type of lemma with
forall x', ?x = x' -> _ =>
(fun kont =>
let x' := fresh "res" in
let H := fresh "res_eq" in
compute_assertion H x' x;
let lemma' := constr:(lemma x' H) in
kont lemma';
(clear H||idtac"ProveLemmaHyp: cleanup failed");
subst x')
| _ => (fun _ => fail "ProveLemmaHyp: lemma not of the expected form")
end.
Ltac ProveLemmaHyps lemma :=
match type of lemma with
forall x', ?x = x' -> _ =>
(fun kont =>
let x' := fresh "res" in
let H := fresh "res_eq" in
compute_assertion H x' x;
let lemma' := constr:(lemma x' H) in
ProveLemmaHyps lemma' kont;
(clear H||idtac"ProveLemmaHyps: cleanup failed");
subst x')
| _ => (fun kont => kont lemma)
end.
Ltac ApplyLemmaThen lemma expr kont :=
let lem := constr:(lemma expr) in
ProveLemmaHyp lem ltac:(fun lem' =>
let Heq := fresh "thm" in
assert (Heq:=lem');
OnMainSubgoal Heq ltac:(type of Heq) ltac:(fun _ => kont Heq);
(clear Heq||idtac"ApplyLemmaThen: cleanup failed")).
Ltac ApplyLemmaThenAndCont lemma expr tac CONT_tac :=
ApplyLemmaThen lemma expr
ltac:(fun lemma' => try tac lemma'; CONT_tac()).
Ltac ReflexiveRewriteTactic
FV_tac SYN_tac LEMMA_tac MAIN_tac fv terms :=
let fv := list_fold_left FV_tac fv terms in
let RW_tac lemma :=
let fcons term CONT_tac :=
let expr := SYN_tac term fv in
let main H :=
match type of H with
| (?req _ ?rhs) => change (req term rhs) in H
end;
MAIN_tac H in
(ApplyLemmaThenAndCont lemma expr main CONT_tac) in
lazy_list_fold_right fcons ltac:(fun _=>idtac) terms in
LEMMA_tac fv RW_tac.
Ltac FV_hypo_tac mkFV req lH :=
let R := relation_carrier req in
let FV_hypo_l_tac h :=
match h with @mkhypo (req ?pe _) _ => mkFV pe end in
let FV_hypo_r_tac h :=
match h with @mkhypo (req _ ?pe) _ => mkFV pe end in
let fv := list_fold_right FV_hypo_l_tac (@nil R) lH in
list_fold_right FV_hypo_r_tac fv lH.
Ltac mkHyp_tac C req Reify lH :=
let mkHyp h res :=
match h with
| @mkhypo (req ?r1 ?r2) _ =>
let pe1 := Reify r1 in
let pe2 := Reify r2 in
constr:(cons ( pe1 , pe2 ) res)
| _ => fail 1 "hypothesis is not a ring equality"
end in
list_fold_right mkHyp (@nil (PExpr C * PExpr C)) lH.
Ltac proofHyp_tac lH :=
let get_proof h :=
match h with
| @mkhypo _ ?p => p
end in
let rec bh l :=
match l with
| nil => constr:(I)
| cons ?h nil => get_proof h
| cons ?h ?tl =>
let l := get_proof h in
let r := bh tl in
constr:(conj l r)
end in
bh lH.
Ltac get_MonPol lemma :=
match type of lemma with
| context [(mk_monpol_list ?cO ?cI ?cadd ?cmul ?csub ?copp ?cdiv ?ceqb _)] =>
constr:(mk_monpol_list cO cI cadd cmul csub copp cdiv ceqb)
| _ => fail 1 "ring/field anomaly: bad correctness lemma (get_MonPol)"
end.
Ltac FV Cst CstPow add mul sub opp pow t fv :=
let rec TFV t fv :=
let f :=
match Cst t with
| NotConstant =>
match t with
| (add ?t1 ?t2) => fun _ => TFV t2 ltac:(TFV t1 fv)
| (mul ?t1 ?t2) => fun _ => TFV t2 ltac:(TFV t1 fv)
| (sub ?t1 ?t2) => fun _ => TFV t2 ltac:(TFV t1 fv)
| (opp ?t1) => fun _ => TFV t1 fv
| (pow ?t1 ?n) =>
match CstPow n with
| InitialRing.NotConstant => fun _ => AddFvTail t fv
| _ => fun _ => TFV t1 fv
end
| _ => fun _ => AddFvTail t fv
end
| _ => fun _ => fv
end in
f()
in TFV t fv.
Ltac mkPolexpr C Cst CstPow radd rmul rsub ropp rpow t fv :=
let rec mkP t :=
let f :=
match Cst t with
| InitialRing.NotConstant =>
match t with
| (radd ?t1 ?t2) =>
fun _ =>
let e1 := mkP t1 in
let e2 := mkP t2 in constr:(PEadd e1 e2)
| (rmul ?t1 ?t2) =>
fun _ =>
let e1 := mkP t1 in
let e2 := mkP t2 in constr:(PEmul e1 e2)
| (rsub ?t1 ?t2) =>
fun _ =>
let e1 := mkP t1 in
let e2 := mkP t2 in constr:(PEsub e1 e2)
| (ropp ?t1) =>
fun _ =>
let e1 := mkP t1 in constr:(PEopp e1)
| (rpow ?t1 ?n) =>
match CstPow n with
| InitialRing.NotConstant =>
fun _ => let p := Find_at t fv in constr:(PEX C p)
| ?c => fun _ => let e1 := mkP t1 in constr:(PEpow e1 c)
end
| _ =>
fun _ => let p := Find_at t fv in constr:(PEX C p)
end
| ?c => fun _ => constr:(@PEc C c)
end in
f ()
in mkP t.
Ltac PackRing F req sth ext morph arth cst_tac pow_tac lemma1 lemma2 pre post :=
let RNG :=
match type of lemma1 with
| context
[@PEeval ?R ?rO ?add ?mul ?sub ?opp ?C ?phi ?Cpow ?powphi ?pow _ _] =>
(fun proj => proj
cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2)
| _ => fail 1 "field anomaly: bad correctness lemma (parse)"
end in
F RNG.
Ltac get_Carrier RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
R).
Ltac get_Eq RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
req).
Ltac get_Pre RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
pre).
Ltac get_Post RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
post).
Ltac get_NormLemma RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
lemma1).
Ltac get_SimplifyLemma RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
lemma2).
Ltac get_RingFV RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
FV cst_tac pow_tac add mul sub opp pow).
Ltac get_RingMeta RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
mkPolexpr C cst_tac pow_tac add mul sub opp pow).
Ltac get_RingHypTac RNG :=
RNG ltac:(fun cst_tac pow_tac pre post
R req add mul sub opp C Cpow powphi pow lemma1 lemma2 =>
let mkPol := mkPolexpr C cst_tac pow_tac add mul sub opp pow in
fun fv lH => mkHyp_tac C req ltac:(fun t => mkPol t fv) lH).
Definition ring_subst_niter := (10*10*10)%nat.
Ltac Ring RNG lemma lH :=
let req := get_Eq RNG in
OnEquation req ltac:(fun lhs rhs =>
let mkFV := get_RingFV RNG in
let mkPol := get_RingMeta RNG in
let mkHyp := get_RingHypTac RNG in
let fv := FV_hypo_tac mkFV ltac:(get_Eq RNG) lH in
let fv := mkFV lhs fv in
let fv := mkFV rhs fv in
check_fv fv;
let pe1 := mkPol lhs fv in
let pe2 := mkPol rhs fv in
let lpe := mkHyp fv lH in
let vlpe := fresh "hyp_list" in
let vfv := fresh "fv_list" in
pose (vlpe := lpe);
pose (vfv := fv);
(apply (lemma vfv vlpe pe1 pe2)
|| fail "typing error while applying ring");
[ ((let prh := proofHyp_tac lH in exact prh)
|| idtac "can not automatically proof hypothesis :";
idtac " maybe a left member of a hypothesis is not a monomial")
| vm_compute;
(exact (refl_equal true) || fail "not a valid ring equation")]).
Ltac Ring_norm_gen f RNG lemma lH rl :=
let mkFV := get_RingFV RNG in
let mkPol := get_RingMeta RNG in
let mkHyp := get_RingHypTac RNG in
let mk_monpol := get_MonPol lemma in
let fv := FV_hypo_tac mkFV ltac:(get_Eq RNG) lH in
let lemma_tac fv kont :=
let lpe := mkHyp fv lH in
let vlpe := fresh "list_hyp" in
let vlmp := fresh "list_hyp_norm" in
let vlmp_eq := fresh "list_hyp_norm_eq" in
let prh := proofHyp_tac lH in
pose (vlpe := lpe);
compute_assertion vlmp_eq vlmp (mk_monpol vlpe);
let H := fresh "ring_lemma" in
(assert (H := lemma vlpe fv prh vlmp vlmp_eq)
|| fail "type error when build the rewriting lemma");
clear vlmp_eq;
kont H;
(clear H||idtac"Ring_norm_gen: cleanup failed");
subst vlpe vlmp in
let simpl_ring H := (protect_fv "ring" in H; f H) in
ReflexiveRewriteTactic mkFV mkPol lemma_tac simpl_ring fv rl.
Ltac Ring_gen RNG lH rl :=
let lemma := get_NormLemma RNG in
get_Pre RNG ();
Ring RNG (lemma ring_subst_niter) lH.
Tactic Notation (at level 0) "ring" :=
let G := Get_goal in
ring_lookup (PackRing Ring_gen) [] G.
Tactic Notation (at level 0) "ring" "[" constr_list(lH) "]" :=
let G := Get_goal in
ring_lookup (PackRing Ring_gen) [lH] G.
Ltac Ring_simplify_gen f RNG lH rl :=
let lemma := get_SimplifyLemma RNG in
let l := fresh "to_rewrite" in
pose (l:= rl);
generalize (refl_equal l);
unfold l at 2;
get_Pre RNG ();
let rl :=
match goal with
| [|- l = ? RL -> _ ] => RL
| _ => fail 1 "ring_simplify anomaly: bad goal after pre"
end in
let Heq := fresh "Heq" in
intros Heq;clear Heq l;
Ring_norm_gen f RNG (lemma ring_subst_niter) lH rl;
get_Post RNG ().
Ltac Ring_simplify := Ring_simplify_gen ltac:(fun H => rewrite H).
Tactic Notation (at level 0) "ring_simplify" constr_list(rl) :=
let G := Get_goal in
ring_lookup (PackRing Ring_simplify) [] rl G.
Tactic Notation (at level 0)
"ring_simplify" "[" constr_list(lH) "]" constr_list(rl) :=
let G := Get_goal in
ring_lookup (PackRing Ring_simplify) [lH] rl G.
Tactic Notation "ring_simplify" constr_list(rl) "in" hyp(H):=
let G := Get_goal in
let t := type of H in
let g := fresh "goal" in
set (g:= G);
generalize H;clear H;
ring_lookup (PackRing Ring_simplify) [] rl t;
intro H;
unfold g;clear g.
Tactic Notation
"ring_simplify" "["constr_list(lH)"]" constr_list(rl) "in" hyp(H):=
let G := Get_goal in
let t := type of H in
let g := fresh "goal" in
set (g:= G);
generalize H;clear H;
ring_lookup (PackRing Ring_simplify) [lH] rl t;
intro H;
unfold g;clear g.