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Mathlib.Algebra.GroupPower.Order

Lemmas about the interaction of power operations with order #

Note that some lemmas are in Algebra/GroupPower/Lemmas.lean as they import files which depend on this file.

theorem CanonicallyOrderedCommSemiring.pow_pos {R : Type u_2} [CanonicallyOrderedCommSemiring R] {a : R} (H : 0 < a) (n : ) :
0 < a ^ n
theorem zero_pow_le_one {R : Type u_2} [OrderedSemiring R] (n : ) :
0 ^ n 1
theorem pow_add_pow_le {R : Type u_2} [OrderedSemiring R] {x : R} {y : R} {n : } (hx : 0 x) (hy : 0 y) (hn : n 0) :
x ^ n + y ^ n (x + y) ^ n
theorem pow_le_one {R : Type u_2} [OrderedSemiring R] {a : R} (n : ) :
0 aa 1a ^ n 1
theorem pow_lt_one {R : Type u_2} [OrderedSemiring R] {a : R} (h₀ : 0 a) (h₁ : a < 1) {n : } :
n 0a ^ n < 1
theorem one_le_pow_of_one_le {R : Type u_2} [OrderedSemiring R] {a : R} (H : 1 a) (n : ) :
1 a ^ n
theorem pow_mono {R : Type u_2} [OrderedSemiring R] {a : R} (h : 1 a) :
Monotone fun (n : ) => a ^ n
theorem pow_le_pow {R : Type u_2} [OrderedSemiring R] {a : R} {n : } {m : } (ha : 1 a) (h : n m) :
a ^ n a ^ m
theorem le_self_pow {R : Type u_2} [OrderedSemiring R] {a : R} {m : } (ha : 1 a) (h : m 0) :
a a ^ m
theorem pow_le_pow_of_le_left {R : Type u_2} [OrderedSemiring R] {a : R} {b : R} (ha : 0 a) (hab : a b) (i : ) :
a ^ i b ^ i
theorem one_lt_pow {R : Type u_2} [OrderedSemiring R] {a : R} (ha : 1 < a) {n : } :
n 01 < a ^ n
theorem pow_lt_pow_of_lt_left {R : Type u_2} [StrictOrderedSemiring R] {x : R} {y : R} (h : x < y) (hx : 0 x) {n : } :
0 < nx ^ n < y ^ n
theorem strictMonoOn_pow {R : Type u_2} [StrictOrderedSemiring R] {n : } (hn : 0 < n) :
StrictMonoOn (fun (x : R) => x ^ n) (Set.Ici 0)
theorem pow_strictMono_right {R : Type u_2} [StrictOrderedSemiring R] {a : R} (h : 1 < a) :
StrictMono fun (n : ) => a ^ n
theorem pow_lt_pow {R : Type u_2} [StrictOrderedSemiring R] {a : R} {n : } {m : } (h : 1 < a) (h2 : n < m) :
a ^ n < a ^ m
theorem pow_lt_pow_iff {R : Type u_2} [StrictOrderedSemiring R] {a : R} {n : } {m : } (h : 1 < a) :
a ^ n < a ^ m n < m
theorem pow_le_pow_iff {R : Type u_2} [StrictOrderedSemiring R] {a : R} {n : } {m : } (h : 1 < a) :
a ^ n a ^ m n m
theorem self_lt_pow {R : Type u_2} [StrictOrderedSemiring R] {a : R} {m : } (h : 1 < a) (h2 : 1 < m) :
a < a ^ m
theorem self_le_pow {R : Type u_2} [StrictOrderedSemiring R] {a : R} {m : } (h : 1 a) (h2 : 1 m) :
a a ^ m
theorem strictAnti_pow {R : Type u_2} [StrictOrderedSemiring R] {a : R} (h₀ : 0 < a) (h₁ : a < 1) :
StrictAnti fun (n : ) => a ^ n
theorem pow_lt_pow_iff_of_lt_one {R : Type u_2} [StrictOrderedSemiring R] {a : R} {n : } {m : } (h₀ : 0 < a) (h₁ : a < 1) :
a ^ m < a ^ n n < m
theorem pow_lt_pow_of_lt_one {R : Type u_2} [StrictOrderedSemiring R] {a : R} (h : 0 < a) (ha : a < 1) {i : } {j : } (hij : i < j) :
a ^ j < a ^ i
theorem pow_lt_self_of_lt_one {R : Type u_2} [StrictOrderedSemiring R] {a : R} {n : } (h₀ : 0 < a) (h₁ : a < 1) (hn : 1 < n) :
a ^ n < a
theorem sq_pos_of_pos {R : Type u_2} [StrictOrderedSemiring R] {a : R} (ha : 0 < a) :
0 < a ^ 2
theorem pow_bit0_pos_of_neg {R : Type u_2} [StrictOrderedRing R] {a : R} (ha : a < 0) (n : ) :
0 < a ^ bit0 n
theorem pow_bit1_neg {R : Type u_2} [StrictOrderedRing R] {a : R} (ha : a < 0) (n : ) :
a ^ bit1 n < 0
theorem sq_pos_of_neg {R : Type u_2} [StrictOrderedRing R] {a : R} (ha : a < 0) :
0 < a ^ 2
theorem pow_le_one_iff_of_nonneg {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) {n : } (hn : n 0) :
a ^ n 1 a 1
theorem one_le_pow_iff_of_nonneg {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) {n : } (hn : n 0) :
1 a ^ n 1 a
theorem pow_eq_one_iff_of_nonneg {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) {n : } (hn : n 0) :
a ^ n = 1 a = 1
theorem one_lt_pow_iff_of_nonneg {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) {n : } (hn : n 0) :
1 < a ^ n 1 < a
theorem pow_lt_one_iff_of_nonneg {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) {n : } (hn : n 0) :
a ^ n < 1 a < 1
theorem sq_le_one_iff {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) :
a ^ 2 1 a 1
theorem sq_lt_one_iff {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) :
a ^ 2 < 1 a < 1
theorem one_le_sq_iff {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) :
1 a ^ 2 1 a
theorem one_lt_sq_iff {R : Type u_2} [LinearOrderedSemiring R] {a : R} (ha : 0 a) :
1 < a ^ 2 1 < a
@[simp]
theorem pow_left_inj {R : Type u_2} [LinearOrderedSemiring R] {x : R} {y : R} {n : } (Hxpos : 0 x) (Hypos : 0 y) (Hnpos : 0 < n) :
x ^ n = y ^ n x = y
theorem lt_of_pow_lt_pow {R : Type u_2} [LinearOrderedSemiring R] {a : R} {b : R} (n : ) (hb : 0 b) (h : a ^ n < b ^ n) :
a < b
theorem le_of_pow_le_pow {R : Type u_2} [LinearOrderedSemiring R] {a : R} {b : R} (n : ) (hb : 0 b) (hn : 0 < n) (h : a ^ n b ^ n) :
a b
@[simp]
theorem sq_eq_sq {R : Type u_2} [LinearOrderedSemiring R] {a : R} {b : R} (ha : 0 a) (hb : 0 b) :
a ^ 2 = b ^ 2 a = b
theorem lt_of_mul_self_lt_mul_self {R : Type u_2} [LinearOrderedSemiring R] {a : R} {b : R} (hb : 0 b) :
a * a < b * ba < b
theorem pow_abs {R : Type u_2} [LinearOrderedRing R] (a : R) (n : ) :
|a| ^ n = |a ^ n|
theorem abs_neg_one_pow {R : Type u_2} [LinearOrderedRing R] (n : ) :
|(-1) ^ n| = 1
theorem abs_pow_eq_one {R : Type u_2} [LinearOrderedRing R] (a : R) {n : } (h : 0 < n) :
|a ^ n| = 1 |a| = 1
theorem pow_bit0_nonneg {R : Type u_2} [LinearOrderedRing R] (a : R) (n : ) :
0 a ^ bit0 n
theorem sq_nonneg {R : Type u_2} [LinearOrderedRing R] (a : R) :
0 a ^ 2
theorem pow_two_nonneg {R : Type u_2} [LinearOrderedRing R] (a : R) :
0 a ^ 2

Alias of sq_nonneg.

theorem pow_bit0_pos {R : Type u_2} [LinearOrderedRing R] {a : R} (h : a 0) (n : ) :
0 < a ^ bit0 n
theorem sq_pos_of_ne_zero {R : Type u_2} [LinearOrderedRing R] (a : R) (h : a 0) :
0 < a ^ 2
theorem pow_two_pos_of_ne_zero {R : Type u_2} [LinearOrderedRing R] (a : R) (h : a 0) :
0 < a ^ 2

Alias of sq_pos_of_ne_zero.

theorem pow_bit0_pos_iff {R : Type u_2} [LinearOrderedRing R] (a : R) {n : } (hn : n 0) :
0 < a ^ bit0 n a 0
theorem sq_pos_iff {R : Type u_2} [LinearOrderedRing R] (a : R) :
0 < a ^ 2 a 0
@[simp]
theorem sq_abs {R : Type u_2} [LinearOrderedRing R] (x : R) :
|x| ^ 2 = x ^ 2
theorem abs_sq {R : Type u_2} [LinearOrderedRing R] (x : R) :
|x ^ 2| = x ^ 2
theorem sq_lt_sq {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} :
x ^ 2 < y ^ 2 |x| < |y|
theorem sq_lt_sq' {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h1 : -y < x) (h2 : x < y) :
x ^ 2 < y ^ 2
theorem sq_le_sq {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} :
x ^ 2 y ^ 2 |x| |y|
theorem sq_le_sq' {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h1 : -y x) (h2 : x y) :
x ^ 2 y ^ 2
theorem abs_lt_of_sq_lt_sq {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h : x ^ 2 < y ^ 2) (hy : 0 y) :
|x| < y
theorem abs_lt_of_sq_lt_sq' {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h : x ^ 2 < y ^ 2) (hy : 0 y) :
-y < x x < y
theorem abs_le_of_sq_le_sq {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h : x ^ 2 y ^ 2) (hy : 0 y) :
|x| y
theorem abs_le_of_sq_le_sq' {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h : x ^ 2 y ^ 2) (hy : 0 y) :
-y x x y
theorem sq_eq_sq_iff_abs_eq_abs {R : Type u_2} [LinearOrderedRing R] (x : R) (y : R) :
x ^ 2 = y ^ 2 |x| = |y|
@[simp]
theorem sq_le_one_iff_abs_le_one {R : Type u_2} [LinearOrderedRing R] (x : R) :
x ^ 2 1 |x| 1
@[simp]
theorem sq_lt_one_iff_abs_lt_one {R : Type u_2} [LinearOrderedRing R] (x : R) :
x ^ 2 < 1 |x| < 1
@[simp]
theorem one_le_sq_iff_one_le_abs {R : Type u_2} [LinearOrderedRing R] (x : R) :
1 x ^ 2 1 |x|
@[simp]
theorem one_lt_sq_iff_one_lt_abs {R : Type u_2} [LinearOrderedRing R] (x : R) :
1 < x ^ 2 1 < |x|
theorem pow_four_le_pow_two_of_pow_two_le {R : Type u_2} [LinearOrderedRing R] {x : R} {y : R} (h : x ^ 2 y) :
x ^ 4 y ^ 2
theorem two_mul_le_add_sq {R : Type u_2} [LinearOrderedCommRing R] (a : R) (b : R) :
2 * a * b a ^ 2 + b ^ 2

Arithmetic mean-geometric mean (AM-GM) inequality for linearly ordered commutative rings.

theorem two_mul_le_add_pow_two {R : Type u_2} [LinearOrderedCommRing R] (a : R) (b : R) :
2 * a * b a ^ 2 + b ^ 2

Alias of two_mul_le_add_sq.


Arithmetic mean-geometric mean (AM-GM) inequality for linearly ordered commutative rings.

theorem pow_pos_iff {M : Type u_1} [LinearOrderedCommMonoidWithZero M] [NoZeroDivisors M] {a : M} {n : } (hn : 0 < n) :
0 < a ^ n 0 < a
theorem pow_lt_pow_succ {M : Type u_1} [LinearOrderedCommGroupWithZero M] {a : M} {n : } (ha : 1 < a) :
a ^ n < a ^ Nat.succ n
theorem pow_lt_pow₀ {M : Type u_1} [LinearOrderedCommGroupWithZero M] {a : M} {m : } {n : } (ha : 1 < a) (hmn : m < n) :
a ^ m < a ^ n
theorem MonoidHom.map_neg_one {M : Type u_1} {R : Type u_2} [Ring R] [Monoid M] [LinearOrder M] [CovariantClass M M (fun (x x_1 : M) => x * x_1) fun (x x_1 : M) => x x_1] (f : R →* M) :
f (-1) = 1
@[simp]
theorem MonoidHom.map_neg {M : Type u_1} {R : Type u_2} [Ring R] [Monoid M] [LinearOrder M] [CovariantClass M M (fun (x x_1 : M) => x * x_1) fun (x x_1 : M) => x x_1] (f : R →* M) (x : R) :
f (-x) = f x
theorem MonoidHom.map_sub_swap {M : Type u_1} {R : Type u_2} [Ring R] [Monoid M] [LinearOrder M] [CovariantClass M M (fun (x x_1 : M) => x * x_1) fun (x x_1 : M) => x x_1] (f : R →* M) (x : R) (y : R) :
f (x - y) = f (y - x)