lean4-htt/library/init/core.lean

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/-
Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
notation, basic datatypes and type classes
-/
prelude
notation `Prop` := Type 0
notation `Type₂` := Type 2
notation `Type₃` := Type 3
/- Logical operations and relations -/
reserve prefix `¬`:40
reserve prefix `~`:40
reserve infixr ` ∧ `:35
reserve infixr ` /\ `:35
reserve infixr ` \/ `:30
reserve infixr ` `:30
reserve infix ` <-> `:20
reserve infix ` ↔ `:20
reserve infix ` = `:50
reserve infix ` ≠ `:50
reserve infix ` ≈ `:50
reserve infix ` ~ `:50
reserve infix ` ≡ `:50
reserve infixl ` ⬝ `:75
reserve infixr ` ▸ `:75
reserve infixr ` ▹ `:75
/- types and type constructors -/
reserve infixr ` ⊕ `:30
reserve infixr ` × `:35
/- arithmetic operations -/
reserve infixl ` + `:65
reserve infixl ` - `:65
reserve infixl ` * `:70
reserve infixl ` / `:70
reserve infixl ` % `:70
reserve prefix `-`:100
reserve infix ` ^ `:80
reserve infixr ` ∘ `:90 -- input with \comp
reserve infix ` <= `:50
reserve infix ` ≤ `:50
reserve infix ` < `:50
reserve infix ` >= `:50
reserve infix ` ≥ `:50
reserve infix ` > `:50
/- boolean operations -/
reserve infixl ` && `:70
reserve infixl ` || `:65
/- set operations -/
reserve infix ` ∈ `:50
reserve infix ` ∉ `:50
reserve infixl ` ∩ `:70
reserve infixl ` `:65
reserve infix ` ⊆ `:50
reserve infix ` ⊇ `:50
reserve infix ` ⊂ `:50
reserve infix ` ⊃ `:50
reserve infix ` \ `:70
/- other symbols -/
reserve infix ` `:50
reserve infixl ` ++ `:65
reserve infixr ` :: `:67
reserve infixl `; `:1
universe variables u v
inductive poly_unit : Type u
| star : poly_unit
inductive unit : Type
| star : unit
inductive true : Prop
| intro : true
inductive false : Prop
inductive empty : Type
def not (a : Prop) := a → false
prefix `¬` := not
inductive eq {A : Type u} (a : A) : A → Prop
| refl : eq a
inductive heq {A : Type u} (a : A) : Π {B : Type u}, B → Prop
| refl : heq a
structure prod (A : Type u) (B : Type v) :=
(fst : A) (snd : B)
inductive and (a b : Prop) : Prop
| intro : a → b → and
def and.elim_left {a b : Prop} (H : and a b) : a :=
and.rec (λ Ha Hb, Ha) H
def and.left := @and.elim_left
def and.elim_right {a b : Prop} (H : and a b) : b :=
and.rec (λ Ha Hb, Hb) H
def and.right := @and.elim_right
inductive sum (A : Type u) (B : Type v)
| inl {} : A → sum
| inr {} : B → sum
inductive or (a b : Prop) : Prop
| inl {} : a → or
| inr {} : b → or
def or.intro_left {a : Prop} (b : Prop) (Ha : a) : or a b :=
or.inl Ha
def or.intro_right (a : Prop) {b : Prop} (Hb : b) : or a b :=
or.inr Hb
structure sigma {A : Type u} (B : A → Type v) :=
mk :: (fst : A) (snd : B fst)
-- pos_num and num are two auxiliary datatypes used when parsing numerals such as 13, 0, 26.
-- The parser will generate the terms (pos (bit1 (bit1 (bit0 one)))), zero, and (pos (bit0 (bit1 (bit1 one)))).
-- This representation can be coerced in whatever we want (e.g., naturals, integers, reals, etc).
inductive pos_num : Type
| one : pos_num
| bit1 : pos_num → pos_num
| bit0 : pos_num → pos_num
namespace pos_num
def succ (a : pos_num) : pos_num :=
pos_num.rec_on a (bit0 one) (λ n r, bit0 r) (λ n r, bit1 n)
end pos_num
inductive num : Type
| zero : num
| pos : pos_num → num
namespace num
open pos_num
def succ (a : num) : num :=
num.rec_on a (pos one) (λ p, pos (succ p))
end num
inductive bool : Type
| ff : bool
| tt : bool
class inductive decidable (p : Prop)
| is_false : ¬p → decidable
| is_true : p → decidable
@[reducible]
def decidable_pred {A : Type u} (r : A → Prop) :=
Π (a : A), decidable (r a)
@[reducible]
def decidable_rel {A : Type u} (r : A → A → Prop) :=
Π (a b : A), decidable (r a b)
@[reducible]
def decidable_eq (A : Type u) :=
decidable_rel (@eq A)
inductive option (A : Type u)
| none {} : option
| some : A → option
export option (none some)
export bool (ff tt)
inductive list (T : Type u)
| nil {} : list
| cons : T → list → list
inductive nat
| zero : nat
| succ : nat → nat
structure unification_constraint :=
{A : Type u} (lhs : A) (rhs : A)
infix ` ≟ `:50 := unification_constraint.mk
infix ` =?= `:50 := unification_constraint.mk
structure unification_hint :=
(pattern : unification_constraint)
(constraints : list unification_constraint)
/- Declare builtin and reserved notation -/
class has_zero (A : Type u) := (zero : A)
class has_one (A : Type u) := (one : A)
class has_add (A : Type u) := (add : A → A → A)
class has_mul (A : Type u) := (mul : A → A → A)
class has_inv (A : Type u) := (inv : A → A)
class has_neg (A : Type u) := (neg : A → A)
class has_sub (A : Type u) := (sub : A → A → A)
class has_div (A : Type u) := (div : A → A → A)
class has_dvd (A : Type u) := (dvd : A → A → Prop)
class has_mod (A : Type u) := (mod : A → A → A)
class has_le (A : Type u) := (le : A → A → Prop)
class has_lt (A : Type u) := (lt : A → A → Prop)
class has_append (A : Type u) := (append : A → A → A)
class has_andthen (A : Type u) := (andthen : A → A → A)
class has_union (A : Type u) := (union : A → A → A)
class has_inter (A : Type u) := (inter : A → A → A)
class has_sdiff (A : Type u) := (sdiff : A → A → A)
class has_subset (A : Type u) := (subset : A → A → Prop)
class has_ssubset (A : Type u) := (ssubset : A → A → Prop)
/- Type classes has_emptyc and has_insert are
used to implement polymorphic notation for collections.
Example: {a, b, c}. -/
class has_emptyc (A : Type u) := (emptyc : A)
class has_insert (A : Type u) (C : Type u → Type v) := (insert : A → C A → C A)
/- Type class used to implement the notation { a ∈ c | p a } -/
class has_sep (A : Type u) (C : Type u → Type v) :=
(sep : (A → Prop) → C A → C A)
/- Type class for set-like membership -/
class has_mem (A : Type u) (C : Type u → Type v) := (mem : A → C A → Prop)
def zero {A : Type u} [has_zero A] : A := has_zero.zero A
def one {A : Type u} [has_one A] : A := has_one.one A
def add {A : Type u} [has_add A] : A → A → A := has_add.add
def mul {A : Type u} [has_mul A] : A → A → A := has_mul.mul
def sub {A : Type u} [has_sub A] : A → A → A := has_sub.sub
def div {A : Type u} [has_div A] : A → A → A := has_div.div
def dvd {A : Type u} [has_dvd A] : A → A → Prop := has_dvd.dvd
def mod {A : Type u} [has_mod A] : A → A → A := has_mod.mod
def neg {A : Type u} [has_neg A] : A → A := has_neg.neg
def inv {A : Type u} [has_inv A] : A → A := has_inv.inv
def le {A : Type u} [has_le A] : A → A → Prop := has_le.le
def lt {A : Type u} [has_lt A] : A → A → Prop := has_lt.lt
def append {A : Type u} [has_append A] : A → A → A := has_append.append
def andthen {A : Type u} [has_andthen A] : A → A → A := has_andthen.andthen
def union {A : Type u} [has_union A] : A → A → A := has_union.union
def inter {A : Type u} [has_inter A] : A → A → A := has_inter.inter
def sdiff {A : Type u} [has_sdiff A] : A → A → A := has_sdiff.sdiff
def subset {A : Type u} [has_subset A] : A → A → Prop := has_subset.subset
def ssubset {A : Type u} [has_ssubset A] : A → A → Prop := has_ssubset.ssubset
@[reducible]
def ge {A : Type u} [has_le A] (a b : A) : Prop := le b a
@[reducible]
def gt {A : Type u} [has_lt A] (a b : A) : Prop := lt b a
@[reducible]
def superset {A : Type u} [has_subset A] (a b : A) : Prop := subset b a
@[reducible]
def ssuperset {A : Type u} [has_ssubset A] (a b : A) : Prop := ssubset b a
def bit0 {A : Type u} [s : has_add A] (a : A) : A := add a a
def bit1 {A : Type u} [s₁ : has_one A] [s₂ : has_add A] (a : A) : A := add (bit0 a) one
attribute [pattern] zero one bit0 bit1 add
def insert {A : Type u} {C : Type u → Type v} [has_insert A C] : A → C A → C A :=
has_insert.insert
/- The empty collection -/
def emptyc {A : Type u} [has_emptyc A] : A :=
has_emptyc.emptyc A
def singleton {A : Type u} {C : Type u → Type v} [has_emptyc (C A)] [has_insert A C] (a : A) : C A :=
insert a emptyc
def sep {A : Type u} {C : Type u → Type v} [has_sep A C] : (A → Prop) → C A → C A :=
has_sep.sep
def mem {A : Type u} {C : Type u → Type v} [has_mem A C] : A → C A → Prop :=
has_mem.mem
/- num, pos_num instances -/
instance : has_zero num :=
⟨num.zero⟩
instance : has_one num :=
⟨num.pos pos_num.one⟩
instance : has_one pos_num :=
⟨pos_num.one⟩
namespace pos_num
def is_one (a : pos_num) : bool :=
pos_num.rec_on a tt (λ n r, ff) (λ n r, ff)
def pred (a : pos_num) : pos_num :=
pos_num.rec_on a one (λ n r, bit0 n) (λ n r, bool.rec_on (is_one n) (bit1 r) one)
def size (a : pos_num) : pos_num :=
pos_num.rec_on a one (λ n r, succ r) (λ n r, succ r)
def add (a b : pos_num) : pos_num :=
pos_num.rec_on a
succ
(λ n f b, pos_num.rec_on b
(succ (bit1 n))
(λ m r, succ (bit1 (f m)))
(λ m r, bit1 (f m)))
(λ n f b, pos_num.rec_on b
(bit1 n)
(λ m r, bit1 (f m))
(λ m r, bit0 (f m)))
b
end pos_num
instance : has_add pos_num :=
⟨pos_num.add⟩
namespace num
open pos_num
def add (a b : num) : num :=
num.rec_on a b (λ pa, num.rec_on b (pos pa) (λ pb, pos (pos_num.add pa pb)))
end num
instance : has_add num :=
⟨num.add⟩
def std.priority.default : num := 1000
def std.priority.max : num := 4294967295
/- nat basic instances -/
namespace nat
protected def prio := num.add std.priority.default 100
protected def add (a b : nat) : nat :=
nat.rec a (λ b₁ r, nat.succ r) b
def of_pos_num (p : pos_num) : nat :=
pos_num.rec (succ zero) (λ n r, nat.add (nat.add r r) (succ zero)) (λ n r, nat.add r r) p
def of_num (n : num) : nat :=
num.rec zero (λ p, of_pos_num p) n
end nat
instance : has_zero nat := ⟨nat.zero⟩
instance : has_one nat := ⟨nat.succ (nat.zero)⟩
instance : has_add nat := ⟨nat.add⟩
/-
Global declarations of right binding strength
If a module reassigns these, it will be incompatible with other modules that adhere to these
conventions.
When hovering over a symbol, use "C-c C-k" to see how to input it.
-/
def std.prec.max : num := 1024 -- the strength of application, identifiers, (, [, etc.
def std.prec.arrow : num := 25
/-
The next def is "max + 10". It can be used e.g. for postfix operations that should
be stronger than application.
-/
def std.prec.max_plus :=
num.succ (num.succ (num.succ (num.succ (num.succ (num.succ (num.succ (num.succ (num.succ
(num.succ std.prec.max)))))))))
reserve postfix `⁻¹`:std.prec.max_plus -- input with \sy or \-1 or \inv
infix = := eq
infix ∈ := mem
notation a ∉ s := ¬ mem a s
infix + := add
infix * := mul
infix - := sub
infix / := div
infix := dvd
infix % := mod
prefix - := neg
postfix ⁻¹ := inv
infix <= := le
infix >= := ge
infix ≤ := le
infix ≥ := ge
infix < := lt
infix > := gt
infix ++ := append
infix ; := andthen
notation `∅` := emptyc
infix := union
infix ∩ := inter
infix ⊆ := subset
infix ⊇ := superset
infix ⊂ := ssubset
infix ⊃ := ssuperset
infix \ := sdiff
/- eq basic support -/
@[pattern] def rfl {A : Type u} {a : A} : a = a := eq.refl a
namespace eq
variables {A : Type u}
variables {a b c a': A}
attribute [elab_as_eliminator]
theorem subst {P : A → Prop} (H₁ : a = b) (H₂ : P a) : P b :=
eq.rec H₂ H₁
theorem trans (H₁ : a = b) (H₂ : b = c) : a = c :=
subst H₂ H₁
theorem symm : a = b → b = a :=
λ h, eq.rec (refl a) h
end eq
notation H1 ▸ H2 := eq.subst H1 H2
attribute [subst] eq.subst
attribute [refl] eq.refl
attribute [trans] eq.trans
attribute [symm] eq.symm
/- sizeof -/
class has_sizeof (A : Type u) :=
(sizeof : A → nat)
def sizeof {A : Type u} [s : has_sizeof A] : A → nat :=
has_sizeof.sizeof
/-
Declare sizeof instances and lemmas for types declared before has_sizeof.
From now on, the inductive compiler will automatically generate sizeof instances and lemmas.
-/
/- Every type `A` has a default has_sizeof instance that just returns 0 for every element of `A` -/
instance default_has_sizeof (A : Type u) : has_sizeof A :=
⟨λ a, nat.zero⟩
attribute [simp, defeq, simp.sizeof]
def default_has_sizeof_eq (A : Type u) (a : A) : @sizeof A (default_has_sizeof A) a = 0 :=
rfl
instance : has_sizeof nat := ⟨λ a, a⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_nat_eq (a : nat) : sizeof a = a :=
rfl
instance (A : Type u) (B : Type v) [has_sizeof A] [has_sizeof B] : has_sizeof (prod A B) :=
⟨λ p, prod.cases_on p (λ a b, 1 + sizeof a + sizeof b)⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_prod_eq {A : Type u} {B : Type v} [has_sizeof A] [has_sizeof B] (a : A) (b : B) : sizeof (prod.mk a b) = 1 + sizeof a + sizeof b :=
rfl
instance (A : Type u) (B : Type v) [has_sizeof A] [has_sizeof B] : has_sizeof (sum A B) :=
⟨λ s, sum.cases_on s (λ a, 1 + sizeof a) (λ b, 1 + sizeof b)⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_sum_eq_left {A : Type u} {B : Type v} [has_sizeof A] [has_sizeof B] (a : A) : sizeof (@sum.inl A B a) = 1 + sizeof a :=
rfl
attribute [simp, defeq, simp.sizeof]
def sizeof_sum_eq_right {A : Type u} {B : Type v} [has_sizeof A] [has_sizeof B] (b : B) : sizeof (@sum.inr A B b) = 1 + sizeof b :=
rfl
instance (A : Type u) (B : A → Type v) [has_sizeof A] [∀ a, has_sizeof (B a)] : has_sizeof (sigma B) :=
⟨λ p, sigma.cases_on p (λ a b, 1 + sizeof a + sizeof b)⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_sigma_eq {A : Type u} {B : A → Type v} [has_sizeof A] [∀ a, has_sizeof (B a)] (a : A) (b : B a) : sizeof (@sigma.mk A B a b) = 1 + sizeof a + sizeof b :=
rfl
instance : has_sizeof unit := ⟨λ u, 1⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_unit_eq (u : unit) : sizeof u = 1 :=
rfl
instance : has_sizeof poly_unit := ⟨λ u, 1⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_poly_unit_eq (u : poly_unit) : sizeof u = 1 :=
rfl
instance : has_sizeof bool := ⟨λ u, 1⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_bool_eq (b : bool) : sizeof b = 1 :=
rfl
instance : has_sizeof pos_num := ⟨λ p, nat.of_pos_num p⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_pos_num_eq (p : pos_num) : sizeof p = nat.of_pos_num p :=
rfl
instance : has_sizeof num := ⟨λ p, nat.of_num p⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_num_eq (n : num) : sizeof n = nat.of_num n :=
rfl
instance (A : Type u) [has_sizeof A] : has_sizeof (option A) :=
⟨λ o, option.cases_on o 1 (λ a, 1 + sizeof a)⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_option_none_eq (A : Type u) [has_sizeof A] : sizeof (@none A) = 1 :=
rfl
attribute [simp, defeq, simp.sizeof]
def sizeof_option_some_eq {A : Type u} [has_sizeof A] (a : A) : sizeof (some a) = 1 + sizeof a :=
rfl
instance (A : Type u) [has_sizeof A] : has_sizeof (list A) :=
⟨λ l, list.rec_on l 1 (λ a t ih, 1 + sizeof a + ih)⟩
attribute [simp, defeq, simp.sizeof]
def sizeof_list_nil_eq (A : Type u) [has_sizeof A] : sizeof (@list.nil A) = 1 :=
rfl
attribute [simp, defeq, simp.sizeof]
def sizeof_list_cons_eq {A : Type u} [has_sizeof A] (a : A) (l : list A) : sizeof (list.cons a l) = 1 + sizeof a + sizeof l :=
rfl
attribute [simp.sizeof]
lemma nat_add_zero (n : nat) : n + 0 = n := rfl