diff options
| author | Enrico Tassi | 2015-11-05 11:36:58 +0100 |
|---|---|---|
| committer | Enrico Tassi | 2015-11-05 16:26:24 +0100 |
| commit | 14c9a3a752e8c21b239ff0800089271c5a5ddfb2 (patch) | |
| tree | 8f7095e1702d5ad56003f8d87df84786902dfec0 /mathcomp/basic/tuple.v | |
| parent | 35124d2e255e5f88d99ddc65361d6997b0a2b751 (diff) | |
merge basic/ into ssreflect/
Diffstat (limited to 'mathcomp/basic/tuple.v')
| -rw-r--r-- | mathcomp/basic/tuple.v | 415 |
1 files changed, 0 insertions, 415 deletions
diff --git a/mathcomp/basic/tuple.v b/mathcomp/basic/tuple.v deleted file mode 100644 index a6a154f..0000000 --- a/mathcomp/basic/tuple.v +++ /dev/null @@ -1,415 +0,0 @@ -(* (c) Copyright 2006-2015 Microsoft Corporation and Inria. *) -(* Distributed under the terms of CeCILL-B. *) -Require Import mathcomp.ssreflect.ssreflect. -From mathcomp -Require Import ssrfun ssrbool eqtype ssrnat seq choice fintype. - -Set Implicit Arguments. -Unset Strict Implicit. -Unset Printing Implicit Defensive. - -(******************************************************************************) -(* Tuples, i.e., sequences with a fixed (known) length. We define: *) -(* n.-tuple T == the type of n-tuples of elements of type T. *) -(* [tuple of s] == the tuple whose underlying sequence (value) is s. *) -(* The size of s must be known: specifically, Coq must *) -(* be able to infer a Canonical tuple projecting on s. *) -(* in_tuple s == the (size s)-tuple with value s. *) -(* [tuple] == the empty tuple. *) -(* [tuple x1; ..; xn] == the explicit n.-tuple <x1; ..; xn>. *) -(* [tuple E | i < n] == the n.-tuple with general term E (i : 'I_n is bound *) -(* in E). *) -(* tcast Emn t == the m-tuple t cast as an n-tuple using Emn : m = n. *) -(* As n.-tuple T coerces to seq t, all seq operations (size, nth, ...) can be *) -(* applied to t : n.-tuple T; we provide a few specialized instances when *) -(* avoids the need for a default value. *) -(* tsize t == the size of t (the n in n.-tuple T) *) -(* tnth t i == the i'th component of t, where i : 'I_n. *) -(* [tnth t i] == the i'th component of t, where i : nat and i < n *) -(* is convertible to true. *) -(* thead t == the first element of t, when n is m.+1 for some m. *) -(* Most seq constructors (cons, behead, cat, rcons, belast, take, drop, rot, *) -(* map, ...) can be used to build tuples via the [tuple of s] construct. *) -(* Tuples are actually a subType of seq, and inherit all combinatorial *) -(* structures, including the finType structure. *) -(* Some useful lemmas and definitions: *) -(* tuple0 : [tuple] is the only 0.-tuple *) -(* tupleP : elimination view for n.+1.-tuple *) -(* ord_tuple n : the n.-tuple of all i : 'I_n *) -(******************************************************************************) - -Section Def. - -Variables (n : nat) (T : Type). - -Structure tuple_of : Type := Tuple {tval :> seq T; _ : size tval == n}. - -Canonical tuple_subType := Eval hnf in [subType for tval]. - -Implicit Type t : tuple_of. - -Definition tsize of tuple_of := n. - -Lemma size_tuple t : size t = n. -Proof. exact: (eqP (valP t)). Qed. - -Lemma tnth_default t : 'I_n -> T. -Proof. by rewrite -(size_tuple t); case: (tval t) => [|//] []. Qed. - -Definition tnth t i := nth (tnth_default t i) t i. - -Lemma tnth_nth x t i : tnth t i = nth x t i. -Proof. by apply: set_nth_default; rewrite size_tuple. Qed. - -Lemma map_tnth_enum t : map (tnth t) (enum 'I_n) = t. -Proof. -case def_t: {-}(val t) => [|x0 t']. - by rewrite [enum _]size0nil // -cardE card_ord -(size_tuple t) def_t. -apply: (@eq_from_nth _ x0) => [|i]; rewrite size_map. - by rewrite -cardE size_tuple card_ord. -move=> lt_i_e; have lt_i_n: i < n by rewrite -cardE card_ord in lt_i_e. -by rewrite (nth_map (Ordinal lt_i_n)) // (tnth_nth x0) nth_enum_ord. -Qed. - -Lemma eq_from_tnth t1 t2 : tnth t1 =1 tnth t2 -> t1 = t2. -Proof. -by move/eq_map=> eq_t; apply: val_inj; rewrite /= -!map_tnth_enum eq_t. -Qed. - -Definition tuple t mkT : tuple_of := - mkT (let: Tuple _ tP := t return size t == n in tP). - -Lemma tupleE t : tuple (fun sP => @Tuple t sP) = t. -Proof. by case: t. Qed. - -End Def. - -Notation "n .-tuple" := (tuple_of n) - (at level 2, format "n .-tuple") : type_scope. - -Notation "{ 'tuple' n 'of' T }" := (n.-tuple T : predArgType) - (at level 0, only parsing) : form_scope. - -Notation "[ 'tuple' 'of' s ]" := (tuple (fun sP => @Tuple _ _ s sP)) - (at level 0, format "[ 'tuple' 'of' s ]") : form_scope. - -Notation "[ 'tnth' t i ]" := (tnth t (@Ordinal (tsize t) i (erefl true))) - (at level 0, t, i at level 8, format "[ 'tnth' t i ]") : form_scope. - -Canonical nil_tuple T := Tuple (isT : @size T [::] == 0). -Canonical cons_tuple n T x (t : n.-tuple T) := - Tuple (valP t : size (x :: t) == n.+1). - -Notation "[ 'tuple' x1 ; .. ; xn ]" := [tuple of x1 :: .. [:: xn] ..] - (at level 0, format "[ 'tuple' '[' x1 ; '/' .. ; '/' xn ']' ]") - : form_scope. - -Notation "[ 'tuple' ]" := [tuple of [::]] - (at level 0, format "[ 'tuple' ]") : form_scope. - -Section CastTuple. - -Variable T : Type. - -Definition in_tuple (s : seq T) := Tuple (eqxx (size s)). - -Definition tcast m n (eq_mn : m = n) t := - let: erefl in _ = n := eq_mn return n.-tuple T in t. - -Lemma tcastE m n (eq_mn : m = n) t i : - tnth (tcast eq_mn t) i = tnth t (cast_ord (esym eq_mn) i). -Proof. by case: n / eq_mn in i *; rewrite cast_ord_id. Qed. - -Lemma tcast_id n (eq_nn : n = n) t : tcast eq_nn t = t. -Proof. by rewrite (eq_axiomK eq_nn). Qed. - -Lemma tcastK m n (eq_mn : m = n) : cancel (tcast eq_mn) (tcast (esym eq_mn)). -Proof. by case: n / eq_mn. Qed. - -Lemma tcastKV m n (eq_mn : m = n) : cancel (tcast (esym eq_mn)) (tcast eq_mn). -Proof. by case: n / eq_mn. Qed. - -Lemma tcast_trans m n p (eq_mn : m = n) (eq_np : n = p) t: - tcast (etrans eq_mn eq_np) t = tcast eq_np (tcast eq_mn t). -Proof. by case: n / eq_mn eq_np; case: p /. Qed. - -Lemma tvalK n (t : n.-tuple T) : in_tuple t = tcast (esym (size_tuple t)) t. -Proof. by apply: val_inj => /=; case: _ / (esym _). Qed. - -Lemma in_tupleE s : in_tuple s = s :> seq T. Proof. by []. Qed. - -End CastTuple. - -Section SeqTuple. - -Variables (n m : nat) (T U rT : Type). -Implicit Type t : n.-tuple T. - -Lemma rcons_tupleP t x : size (rcons t x) == n.+1. -Proof. by rewrite size_rcons size_tuple. Qed. -Canonical rcons_tuple t x := Tuple (rcons_tupleP t x). - -Lemma nseq_tupleP x : @size T (nseq n x) == n. -Proof. by rewrite size_nseq. Qed. -Canonical nseq_tuple x := Tuple (nseq_tupleP x). - -Lemma iota_tupleP : size (iota m n) == n. -Proof. by rewrite size_iota. Qed. -Canonical iota_tuple := Tuple iota_tupleP. - -Lemma behead_tupleP t : size (behead t) == n.-1. -Proof. by rewrite size_behead size_tuple. Qed. -Canonical behead_tuple t := Tuple (behead_tupleP t). - -Lemma belast_tupleP x t : size (belast x t) == n. -Proof. by rewrite size_belast size_tuple. Qed. -Canonical belast_tuple x t := Tuple (belast_tupleP x t). - -Lemma cat_tupleP t (u : m.-tuple T) : size (t ++ u) == n + m. -Proof. by rewrite size_cat !size_tuple. Qed. -Canonical cat_tuple t u := Tuple (cat_tupleP t u). - -Lemma take_tupleP t : size (take m t) == minn m n. -Proof. by rewrite size_take size_tuple eqxx. Qed. -Canonical take_tuple t := Tuple (take_tupleP t). - -Lemma drop_tupleP t : size (drop m t) == n - m. -Proof. by rewrite size_drop size_tuple. Qed. -Canonical drop_tuple t := Tuple (drop_tupleP t). - -Lemma rev_tupleP t : size (rev t) == n. -Proof. by rewrite size_rev size_tuple. Qed. -Canonical rev_tuple t := Tuple (rev_tupleP t). - -Lemma rot_tupleP t : size (rot m t) == n. -Proof. by rewrite size_rot size_tuple. Qed. -Canonical rot_tuple t := Tuple (rot_tupleP t). - -Lemma rotr_tupleP t : size (rotr m t) == n. -Proof. by rewrite size_rotr size_tuple. Qed. -Canonical rotr_tuple t := Tuple (rotr_tupleP t). - -Lemma map_tupleP f t : @size rT (map f t) == n. -Proof. by rewrite size_map size_tuple. Qed. -Canonical map_tuple f t := Tuple (map_tupleP f t). - -Lemma scanl_tupleP f x t : @size rT (scanl f x t) == n. -Proof. by rewrite size_scanl size_tuple. Qed. -Canonical scanl_tuple f x t := Tuple (scanl_tupleP f x t). - -Lemma pairmap_tupleP f x t : @size rT (pairmap f x t) == n. -Proof. by rewrite size_pairmap size_tuple. Qed. -Canonical pairmap_tuple f x t := Tuple (pairmap_tupleP f x t). - -Lemma zip_tupleP t (u : n.-tuple U) : size (zip t u) == n. -Proof. by rewrite size1_zip !size_tuple. Qed. -Canonical zip_tuple t u := Tuple (zip_tupleP t u). - -Lemma allpairs_tupleP f t (u : m.-tuple U) : @size rT (allpairs f t u) == n * m. -Proof. by rewrite size_allpairs !size_tuple. Qed. -Canonical allpairs_tuple f t u := Tuple (allpairs_tupleP f t u). - -Definition thead (u : n.+1.-tuple T) := tnth u ord0. - -Lemma tnth0 x t : tnth [tuple of x :: t] ord0 = x. -Proof. by []. Qed. - -Lemma theadE x t : thead [tuple of x :: t] = x. -Proof. by []. Qed. - -Lemma tuple0 : all_equal_to ([tuple] : 0.-tuple T). -Proof. by move=> t; apply: val_inj; case: t => [[]]. Qed. - -CoInductive tuple1_spec : n.+1.-tuple T -> Type := - Tuple1spec x t : tuple1_spec [tuple of x :: t]. - -Lemma tupleP u : tuple1_spec u. -Proof. -case: u => [[|x s] //= sz_s]; pose t := @Tuple n _ s sz_s. -by rewrite (_ : Tuple _ = [tuple of x :: t]) //; apply: val_inj. -Qed. - -Lemma tnth_map f t i : tnth [tuple of map f t] i = f (tnth t i) :> rT. -Proof. by apply: nth_map; rewrite size_tuple. Qed. - -End SeqTuple. - -Lemma tnth_behead n T (t : n.+1.-tuple T) i : - tnth [tuple of behead t] i = tnth t (inord i.+1). -Proof. by case/tupleP: t => x t; rewrite !(tnth_nth x) inordK ?ltnS. Qed. - -Lemma tuple_eta n T (t : n.+1.-tuple T) : t = [tuple of thead t :: behead t]. -Proof. by case/tupleP: t => x t; apply: val_inj. Qed. - -Section TupleQuantifiers. - -Variables (n : nat) (T : Type). -Implicit Types (a : pred T) (t : n.-tuple T). - -Lemma forallb_tnth a t : [forall i, a (tnth t i)] = all a t. -Proof. -apply: negb_inj; rewrite -has_predC -has_map negb_forall. -apply/existsP/(has_nthP true) => [[i a_t_i] | [i lt_i_n a_t_i]]. - by exists i; rewrite ?size_tuple // -tnth_nth tnth_map. -rewrite size_tuple in lt_i_n; exists (Ordinal lt_i_n). -by rewrite -tnth_map (tnth_nth true). -Qed. - -Lemma existsb_tnth a t : [exists i, a (tnth t i)] = has a t. -Proof. by apply: negb_inj; rewrite negb_exists -all_predC -forallb_tnth. Qed. - -Lemma all_tnthP a t : reflect (forall i, a (tnth t i)) (all a t). -Proof. by rewrite -forallb_tnth; apply: forallP. Qed. - -Lemma has_tnthP a t : reflect (exists i, a (tnth t i)) (has a t). -Proof. by rewrite -existsb_tnth; apply: existsP. Qed. - -End TupleQuantifiers. - -Implicit Arguments all_tnthP [n T a t]. -Implicit Arguments has_tnthP [n T a t]. - -Section EqTuple. - -Variables (n : nat) (T : eqType). - -Definition tuple_eqMixin := Eval hnf in [eqMixin of n.-tuple T by <:]. -Canonical tuple_eqType := Eval hnf in EqType (n.-tuple T) tuple_eqMixin. - -Canonical tuple_predType := - Eval hnf in mkPredType (fun t : n.-tuple T => mem_seq t). - -Lemma memtE (t : n.-tuple T) : mem t = mem (tval t). -Proof. by []. Qed. - -Lemma mem_tnth i (t : n.-tuple T) : tnth t i \in t. -Proof. by rewrite mem_nth ?size_tuple. Qed. - -Lemma memt_nth x0 (t : n.-tuple T) i : i < n -> nth x0 t i \in t. -Proof. by move=> i_lt_n; rewrite mem_nth ?size_tuple. Qed. - -Lemma tnthP (t : n.-tuple T) x : reflect (exists i, x = tnth t i) (x \in t). -Proof. -apply: (iffP idP) => [/(nthP x)[i ltin <-] | [i ->]]; last exact: mem_tnth. -by rewrite size_tuple in ltin; exists (Ordinal ltin); rewrite (tnth_nth x). -Qed. - -Lemma seq_tnthP (s : seq T) x : x \in s -> {i | x = tnth (in_tuple s) i}. -Proof. -move=> s_x; pose i := index x s; have lt_i: i < size s by rewrite index_mem. -by exists (Ordinal lt_i); rewrite (tnth_nth x) nth_index. -Qed. - -End EqTuple. - -Definition tuple_choiceMixin n (T : choiceType) := - [choiceMixin of n.-tuple T by <:]. - -Canonical tuple_choiceType n (T : choiceType) := - Eval hnf in ChoiceType (n.-tuple T) (tuple_choiceMixin n T). - -Definition tuple_countMixin n (T : countType) := - [countMixin of n.-tuple T by <:]. - -Canonical tuple_countType n (T : countType) := - Eval hnf in CountType (n.-tuple T) (tuple_countMixin n T). - -Canonical tuple_subCountType n (T : countType) := - Eval hnf in [subCountType of n.-tuple T]. - -Module Type FinTupleSig. -Section FinTupleSig. -Variables (n : nat) (T : finType). -Parameter enum : seq (n.-tuple T). -Axiom enumP : Finite.axiom enum. -Axiom size_enum : size enum = #|T| ^ n. -End FinTupleSig. -End FinTupleSig. - -Module FinTuple : FinTupleSig. -Section FinTuple. -Variables (n : nat) (T : finType). - -Definition enum : seq (n.-tuple T) := - let extend e := flatten (codom (fun x => map (cons x) e)) in - pmap insub (iter n extend [::[::]]). - -Lemma enumP : Finite.axiom enum. -Proof. -case=> /= t t_n; rewrite -(count_map _ (pred1 t)) (pmap_filter (@insubK _ _ _)). -rewrite count_filter -(@eq_count _ (pred1 t)) => [|s /=]; last first. - by rewrite isSome_insub; case: eqP=> // ->. -elim: n t t_n => [|m IHm] [|x t] //= {IHm}/IHm; move: (iter m _ _) => em IHm. -transitivity (x \in T : nat); rewrite // -mem_enum codomE. -elim: (fintype.enum T) (enum_uniq T) => //= y e IHe /andP[/negPf ney]. -rewrite count_cat count_map inE /preim /= {1}/eq_op /= eq_sym => /IHe->. -by case: eqP => [->|_]; rewrite ?(ney, count_pred0, IHm). -Qed. - -Lemma size_enum : size enum = #|T| ^ n. -Proof. -rewrite /= cardE size_pmap_sub; elim: n => //= m IHm. -rewrite expnS /codom /image_mem; elim: {2 3}(fintype.enum T) => //= x e IHe. -by rewrite count_cat {}IHe count_map IHm. -Qed. - -End FinTuple. -End FinTuple. - -Section UseFinTuple. - -Variables (n : nat) (T : finType). - -Canonical tuple_finMixin := Eval hnf in FinMixin (@FinTuple.enumP n T). -Canonical tuple_finType := Eval hnf in FinType (n.-tuple T) tuple_finMixin. -Canonical tuple_subFinType := Eval hnf in [subFinType of n.-tuple T]. - -Lemma card_tuple : #|{:n.-tuple T}| = #|T| ^ n. -Proof. by rewrite [#|_|]cardT enumT unlock FinTuple.size_enum. Qed. - -Lemma enum_tupleP (A : pred T) : size (enum A) == #|A|. -Proof. by rewrite -cardE. Qed. -Canonical enum_tuple A := Tuple (enum_tupleP A). - -Definition ord_tuple : n.-tuple 'I_n := Tuple (introT eqP (size_enum_ord n)). -Lemma val_ord_tuple : val ord_tuple = enum 'I_n. Proof. by []. Qed. - -Lemma tuple_map_ord U (t : n.-tuple U) : t = [tuple of map (tnth t) ord_tuple]. -Proof. by apply: val_inj => /=; rewrite map_tnth_enum. Qed. - -Lemma tnth_ord_tuple i : tnth ord_tuple i = i. -Proof. -apply: val_inj; rewrite (tnth_nth i) -(nth_map _ 0) ?size_tuple //. -by rewrite /= enumT unlock val_ord_enum nth_iota. -Qed. - -Section ImageTuple. - -Variables (T' : Type) (f : T -> T') (A : pred T). - -Canonical image_tuple : #|A|.-tuple T' := [tuple of image f A]. -Canonical codom_tuple : #|T|.-tuple T' := [tuple of codom f]. - -End ImageTuple. - -Section MkTuple. - -Variables (T' : Type) (f : 'I_n -> T'). - -Definition mktuple := map_tuple f ord_tuple. - -Lemma tnth_mktuple i : tnth mktuple i = f i. -Proof. by rewrite tnth_map tnth_ord_tuple. Qed. - -Lemma nth_mktuple x0 (i : 'I_n) : nth x0 mktuple i = f i. -Proof. by rewrite -tnth_nth tnth_mktuple. Qed. - -End MkTuple. - -End UseFinTuple. - -Notation "[ 'tuple' F | i < n ]" := (mktuple (fun i : 'I_n => F)) - (at level 0, i at level 0, - format "[ '[hv' 'tuple' F '/' | i < n ] ']'") : form_scope. - - |
