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Type | Label | Description |
---|---|---|
Statement | ||
Theorem | 2tp1odd 15701 | A number which is twice an integer increased by 1 is odd. (Contributed by AV, 16-Jul-2021.) |
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 = ((2 · 𝐴) + 1)) → ¬ 2 ∥ 𝐵) | ||
Theorem | mulsucdiv2z 15702 | An integer multiplied with its successor divided by 2 yields an integer, i.e. an integer multiplied with its successor is even. (Contributed by AV, 19-Jul-2021.) |
⊢ (𝑁 ∈ ℤ → ((𝑁 · (𝑁 + 1)) / 2) ∈ ℤ) | ||
Theorem | sqoddm1div8z 15703 | A squared odd number minus 1 divided by 8 is an integer. (Contributed by AV, 19-Jul-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ ¬ 2 ∥ 𝑁) → (((𝑁↑2) − 1) / 8) ∈ ℤ) | ||
Theorem | 2teven 15704 | A number which is twice an integer is even. (Contributed by AV, 16-Jul-2021.) |
⊢ ((𝐴 ∈ ℤ ∧ 𝐵 = (2 · 𝐴)) → 2 ∥ 𝐵) | ||
Theorem | zeo5 15705 | An integer is either even or odd, version of zeo3 15686 avoiding the negation of the representation of an odd number. (Proposed by BJ, 21-Jun-2021.) (Contributed by AV, 26-Jun-2020.) |
⊢ (𝑁 ∈ ℤ → (2 ∥ 𝑁 ∨ 2 ∥ (𝑁 + 1))) | ||
Theorem | evend2 15706 | An integer is even iff its quotient with 2 is an integer. This is a representation of even numbers without using the divides relation, see zeo 12069 and zeo2 12070. (Contributed by AV, 22-Jun-2021.) |
⊢ (𝑁 ∈ ℤ → (2 ∥ 𝑁 ↔ (𝑁 / 2) ∈ ℤ)) | ||
Theorem | oddp1d2 15707 | An integer is odd iff its successor divided by 2 is an integer. This is a representation of odd numbers without using the divides relation, see zeo 12069 and zeo2 12070. (Contributed by AV, 22-Jun-2021.) |
⊢ (𝑁 ∈ ℤ → (¬ 2 ∥ 𝑁 ↔ ((𝑁 + 1) / 2) ∈ ℤ)) | ||
Theorem | zob 15708 | Alternate characterizations of an odd number. (Contributed by AV, 7-Jun-2020.) |
⊢ (𝑁 ∈ ℤ → (((𝑁 + 1) / 2) ∈ ℤ ↔ ((𝑁 − 1) / 2) ∈ ℤ)) | ||
Theorem | oddm1d2 15709 | An integer is odd iff its predecessor divided by 2 is an integer. This is another representation of odd numbers without using the divides relation. (Contributed by AV, 18-Jun-2021.) (Proof shortened by AV, 22-Jun-2021.) |
⊢ (𝑁 ∈ ℤ → (¬ 2 ∥ 𝑁 ↔ ((𝑁 − 1) / 2) ∈ ℤ)) | ||
Theorem | ltoddhalfle 15710 | An integer is less than half of an odd number iff it is less than or equal to the half of the predecessor of the odd number (which is an even number). (Contributed by AV, 29-Jun-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ ¬ 2 ∥ 𝑁 ∧ 𝑀 ∈ ℤ) → (𝑀 < (𝑁 / 2) ↔ 𝑀 ≤ ((𝑁 − 1) / 2))) | ||
Theorem | halfleoddlt 15711 | An integer is greater than half of an odd number iff it is greater than or equal to the half of the odd number. (Contributed by AV, 1-Jul-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ ¬ 2 ∥ 𝑁 ∧ 𝑀 ∈ ℤ) → ((𝑁 / 2) ≤ 𝑀 ↔ (𝑁 / 2) < 𝑀)) | ||
Theorem | opoe 15712 | The sum of two odds is even. (Contributed by Scott Fenton, 7-Apr-2014.) (Revised by Mario Carneiro, 19-Apr-2014.) |
⊢ (((𝐴 ∈ ℤ ∧ ¬ 2 ∥ 𝐴) ∧ (𝐵 ∈ ℤ ∧ ¬ 2 ∥ 𝐵)) → 2 ∥ (𝐴 + 𝐵)) | ||
Theorem | omoe 15713 | The difference of two odds is even. (Contributed by Scott Fenton, 7-Apr-2014.) (Revised by Mario Carneiro, 19-Apr-2014.) |
⊢ (((𝐴 ∈ ℤ ∧ ¬ 2 ∥ 𝐴) ∧ (𝐵 ∈ ℤ ∧ ¬ 2 ∥ 𝐵)) → 2 ∥ (𝐴 − 𝐵)) | ||
Theorem | opeo 15714 | The sum of an odd and an even is odd. (Contributed by Scott Fenton, 7-Apr-2014.) (Revised by Mario Carneiro, 19-Apr-2014.) |
⊢ (((𝐴 ∈ ℤ ∧ ¬ 2 ∥ 𝐴) ∧ (𝐵 ∈ ℤ ∧ 2 ∥ 𝐵)) → ¬ 2 ∥ (𝐴 + 𝐵)) | ||
Theorem | omeo 15715 | The difference of an odd and an even is odd. (Contributed by Scott Fenton, 7-Apr-2014.) (Revised by Mario Carneiro, 19-Apr-2014.) |
⊢ (((𝐴 ∈ ℤ ∧ ¬ 2 ∥ 𝐴) ∧ (𝐵 ∈ ℤ ∧ 2 ∥ 𝐵)) → ¬ 2 ∥ (𝐴 − 𝐵)) | ||
Theorem | z0even 15716 | 2 divides 0. That means 0 is even. (Contributed by AV, 11-Feb-2020.) (Revised by AV, 23-Jun-2021.) |
⊢ 2 ∥ 0 | ||
Theorem | n2dvds1 15717 | 2 does not divide 1. That means 1 is odd. (Contributed by David A. Wheeler, 8-Dec-2018.) (Proof shortened by Steven Nguyen, 3-May-2023.) |
⊢ ¬ 2 ∥ 1 | ||
Theorem | n2dvds1OLD 15718 | Obsolete version of n2dvds1 15717 as of 3-May-2023. 2 does not divide 1. That means 1 is odd. (Contributed by David A. Wheeler, 8-Dec-2018.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ ¬ 2 ∥ 1 | ||
Theorem | n2dvdsm1 15719 | 2 does not divide -1. That means -1 is odd. (Contributed by AV, 15-Aug-2021.) |
⊢ ¬ 2 ∥ -1 | ||
Theorem | z2even 15720 | 2 divides 2. That means 2 is even. (Contributed by AV, 12-Feb-2020.) (Revised by AV, 23-Jun-2021.) |
⊢ 2 ∥ 2 | ||
Theorem | n2dvds3 15721 | 2 does not divide 3. That means 3 is odd. (Contributed by AV, 28-Feb-2021.) (Proof shortened by Steven Nguyen, 3-May-2023.) |
⊢ ¬ 2 ∥ 3 | ||
Theorem | n2dvds3OLD 15722 | Obsolete version of n2dvds3 15721 as of 3-May-2023. 2 does not divide 3. That means 3 is odd. (Contributed by AV, 28-Feb-2021.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ ¬ 2 ∥ 3 | ||
Theorem | z4even 15723 | 2 divides 4. That means 4 is even. (Contributed by AV, 23-Jul-2020.) (Revised by AV, 4-Jul-2021.) |
⊢ 2 ∥ 4 | ||
Theorem | 4dvdseven 15724 | An integer which is divisible by 4 is divisible by 2, that is, is even. (Contributed by AV, 4-Jul-2021.) |
⊢ (4 ∥ 𝑁 → 2 ∥ 𝑁) | ||
Theorem | m1expe 15725 | Exponentiation of -1 by an even power. Variant of m1expeven 13477. (Contributed by AV, 25-Jun-2021.) |
⊢ (2 ∥ 𝑁 → (-1↑𝑁) = 1) | ||
Theorem | m1expo 15726 | Exponentiation of -1 by an odd power. (Contributed by AV, 26-Jun-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ ¬ 2 ∥ 𝑁) → (-1↑𝑁) = -1) | ||
Theorem | m1exp1 15727 | Exponentiation of negative one is one iff the exponent is even. (Contributed by AV, 20-Jun-2021.) |
⊢ (𝑁 ∈ ℤ → ((-1↑𝑁) = 1 ↔ 2 ∥ 𝑁)) | ||
Theorem | nn0enne 15728 | A positive integer is an even nonnegative integer iff it is an even positive integer. (Contributed by AV, 30-May-2020.) |
⊢ (𝑁 ∈ ℕ → ((𝑁 / 2) ∈ ℕ0 ↔ (𝑁 / 2) ∈ ℕ)) | ||
Theorem | nn0ehalf 15729 | The half of an even nonnegative integer is a nonnegative integer. (Contributed by AV, 22-Jun-2020.) (Revised by AV, 28-Jun-2021.) (Proof shortened by AV, 10-Jul-2022.) |
⊢ ((𝑁 ∈ ℕ0 ∧ 2 ∥ 𝑁) → (𝑁 / 2) ∈ ℕ0) | ||
Theorem | nnehalf 15730 | The half of an even positive integer is a positive integer. (Contributed by AV, 28-Jun-2021.) |
⊢ ((𝑁 ∈ ℕ ∧ 2 ∥ 𝑁) → (𝑁 / 2) ∈ ℕ) | ||
Theorem | nn0onn 15731 | An odd nonnegative integer is positive. (Contributed by Steven Nguyen, 25-Mar-2023.) |
⊢ ((𝑁 ∈ ℕ0 ∧ ¬ 2 ∥ 𝑁) → 𝑁 ∈ ℕ) | ||
Theorem | nn0o1gt2 15732 | An odd nonnegative integer is either 1 or greater than 2. (Contributed by AV, 2-Jun-2020.) |
⊢ ((𝑁 ∈ ℕ0 ∧ ((𝑁 + 1) / 2) ∈ ℕ0) → (𝑁 = 1 ∨ 2 < 𝑁)) | ||
Theorem | nno 15733 | An alternate characterization of an odd integer greater than 1. (Contributed by AV, 2-Jun-2020.) (Proof shortened by AV, 10-Jul-2022.) |
⊢ ((𝑁 ∈ (ℤ≥‘2) ∧ ((𝑁 + 1) / 2) ∈ ℕ0) → ((𝑁 − 1) / 2) ∈ ℕ) | ||
Theorem | nn0o 15734 | An alternate characterization of an odd nonnegative integer. (Contributed by AV, 28-May-2020.) (Proof shortened by AV, 2-Jun-2020.) |
⊢ ((𝑁 ∈ ℕ0 ∧ ((𝑁 + 1) / 2) ∈ ℕ0) → ((𝑁 − 1) / 2) ∈ ℕ0) | ||
Theorem | nn0ob 15735 | Alternate characterizations of an odd nonnegative integer. (Contributed by AV, 4-Jun-2020.) |
⊢ (𝑁 ∈ ℕ0 → (((𝑁 + 1) / 2) ∈ ℕ0 ↔ ((𝑁 − 1) / 2) ∈ ℕ0)) | ||
Theorem | nn0oddm1d2 15736 | A positive integer is odd iff its predecessor divided by 2 is a positive integer. (Contributed by AV, 28-Jun-2021.) (Proof shortened by AV, 10-Jul-2022.) |
⊢ (𝑁 ∈ ℕ0 → (¬ 2 ∥ 𝑁 ↔ ((𝑁 − 1) / 2) ∈ ℕ0)) | ||
Theorem | nnoddm1d2 15737 | A positive integer is odd iff its successor divided by 2 is a positive integer. (Contributed by AV, 28-Jun-2021.) |
⊢ (𝑁 ∈ ℕ → (¬ 2 ∥ 𝑁 ↔ ((𝑁 + 1) / 2) ∈ ℕ)) | ||
Theorem | sumeven 15738* | If every term in a sum is even, then so is the sum. (Contributed by AV, 14-Aug-2021.) |
⊢ (𝜑 → 𝐴 ∈ Fin) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℤ) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 2 ∥ 𝐵) ⇒ ⊢ (𝜑 → 2 ∥ Σ𝑘 ∈ 𝐴 𝐵) | ||
Theorem | sumodd 15739* | If every term in a sum is odd, then the sum is even iff the number of terms in the sum is even. (Contributed by AV, 14-Aug-2021.) |
⊢ (𝜑 → 𝐴 ∈ Fin) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℤ) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → ¬ 2 ∥ 𝐵) ⇒ ⊢ (𝜑 → (2 ∥ (♯‘𝐴) ↔ 2 ∥ Σ𝑘 ∈ 𝐴 𝐵)) | ||
Theorem | evensumodd 15740* | If every term in a sum with an even number of terms is odd, then the sum is even. (Contributed by AV, 14-Aug-2021.) |
⊢ (𝜑 → 𝐴 ∈ Fin) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℤ) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → ¬ 2 ∥ 𝐵) & ⊢ (𝜑 → 2 ∥ (♯‘𝐴)) ⇒ ⊢ (𝜑 → 2 ∥ Σ𝑘 ∈ 𝐴 𝐵) | ||
Theorem | oddsumodd 15741* | If every term in a sum with an odd number of terms is odd, then the sum is odd. (Contributed by AV, 14-Aug-2021.) |
⊢ (𝜑 → 𝐴 ∈ Fin) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → 𝐵 ∈ ℤ) & ⊢ ((𝜑 ∧ 𝑘 ∈ 𝐴) → ¬ 2 ∥ 𝐵) & ⊢ (𝜑 → ¬ 2 ∥ (♯‘𝐴)) ⇒ ⊢ (𝜑 → ¬ 2 ∥ Σ𝑘 ∈ 𝐴 𝐵) | ||
Theorem | pwp1fsum 15742* | The n-th power of a number increased by 1 expressed by a product with a finite sum. (Contributed by AV, 15-Aug-2021.) |
⊢ (𝜑 → 𝐴 ∈ ℂ) & ⊢ (𝜑 → 𝑁 ∈ ℕ) ⇒ ⊢ (𝜑 → (((-1↑(𝑁 − 1)) · (𝐴↑𝑁)) + 1) = ((𝐴 + 1) · Σ𝑘 ∈ (0...(𝑁 − 1))((-1↑𝑘) · (𝐴↑𝑘)))) | ||
Theorem | oddpwp1fsum 15743* | An odd power of a number increased by 1 expressed by a product with a finite sum. (Contributed by AV, 15-Aug-2021.) |
⊢ (𝜑 → 𝐴 ∈ ℂ) & ⊢ (𝜑 → 𝑁 ∈ ℕ) & ⊢ (𝜑 → ¬ 2 ∥ 𝑁) ⇒ ⊢ (𝜑 → ((𝐴↑𝑁) + 1) = ((𝐴 + 1) · Σ𝑘 ∈ (0...(𝑁 − 1))((-1↑𝑘) · (𝐴↑𝑘)))) | ||
Theorem | divalglem0 15744 | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ ⇒ ⊢ ((𝑅 ∈ ℤ ∧ 𝐾 ∈ ℤ) → (𝐷 ∥ (𝑁 − 𝑅) → 𝐷 ∥ (𝑁 − (𝑅 − (𝐾 · (abs‘𝐷)))))) | ||
Theorem | divalglem1 15745 | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 ⇒ ⊢ 0 ≤ (𝑁 + (abs‘(𝑁 · 𝐷))) | ||
Theorem | divalglem2 15746* | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) (Revised by AV, 2-Oct-2020.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 & ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ 𝐷 ∥ (𝑁 − 𝑟)} ⇒ ⊢ inf(𝑆, ℝ, < ) ∈ 𝑆 | ||
Theorem | divalglem4 15747* | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 & ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ 𝐷 ∥ (𝑁 − 𝑟)} ⇒ ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ ∃𝑞 ∈ ℤ 𝑁 = ((𝑞 · 𝐷) + 𝑟)} | ||
Theorem | divalglem5 15748* | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) (Revised by AV, 2-Oct-2020.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 & ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ 𝐷 ∥ (𝑁 − 𝑟)} & ⊢ 𝑅 = inf(𝑆, ℝ, < ) ⇒ ⊢ (0 ≤ 𝑅 ∧ 𝑅 < (abs‘𝐷)) | ||
Theorem | divalglem6 15749 | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ 𝐴 ∈ ℕ & ⊢ 𝑋 ∈ (0...(𝐴 − 1)) & ⊢ 𝐾 ∈ ℤ ⇒ ⊢ (𝐾 ≠ 0 → ¬ (𝑋 + (𝐾 · 𝐴)) ∈ (0...(𝐴 − 1))) | ||
Theorem | divalglem7 15750 | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 ⇒ ⊢ ((𝑋 ∈ (0...((abs‘𝐷) − 1)) ∧ 𝐾 ∈ ℤ) → (𝐾 ≠ 0 → ¬ (𝑋 + (𝐾 · (abs‘𝐷))) ∈ (0...((abs‘𝐷) − 1)))) | ||
Theorem | divalglem8 15751* | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 & ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ 𝐷 ∥ (𝑁 − 𝑟)} ⇒ ⊢ (((𝑋 ∈ 𝑆 ∧ 𝑌 ∈ 𝑆) ∧ (𝑋 < (abs‘𝐷) ∧ 𝑌 < (abs‘𝐷))) → (𝐾 ∈ ℤ → ((𝐾 · (abs‘𝐷)) = (𝑌 − 𝑋) → 𝑋 = 𝑌))) | ||
Theorem | divalglem9 15752* | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) (Revised by AV, 2-Oct-2020.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 & ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ 𝐷 ∥ (𝑁 − 𝑟)} & ⊢ 𝑅 = inf(𝑆, ℝ, < ) ⇒ ⊢ ∃!𝑥 ∈ 𝑆 𝑥 < (abs‘𝐷) | ||
Theorem | divalglem10 15753* | Lemma for divalg 15754. (Contributed by Paul Chapman, 21-Mar-2011.) (Proof shortened by AV, 2-Oct-2020.) |
⊢ 𝑁 ∈ ℤ & ⊢ 𝐷 ∈ ℤ & ⊢ 𝐷 ≠ 0 & ⊢ 𝑆 = {𝑟 ∈ ℕ0 ∣ 𝐷 ∥ (𝑁 − 𝑟)} ⇒ ⊢ ∃!𝑟 ∈ ℤ ∃𝑞 ∈ ℤ (0 ≤ 𝑟 ∧ 𝑟 < (abs‘𝐷) ∧ 𝑁 = ((𝑞 · 𝐷) + 𝑟)) | ||
Theorem | divalg 15754* | The division algorithm (theorem). Dividing an integer 𝑁 by a nonzero integer 𝐷 produces a (unique) quotient 𝑞 and a unique remainder 0 ≤ 𝑟 < (abs‘𝐷). Theorem 1.14 in [ApostolNT] p. 19. The proof does not use / or ⌊ or mod. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℤ ∧ 𝐷 ≠ 0) → ∃!𝑟 ∈ ℤ ∃𝑞 ∈ ℤ (0 ≤ 𝑟 ∧ 𝑟 < (abs‘𝐷) ∧ 𝑁 = ((𝑞 · 𝐷) + 𝑟))) | ||
Theorem | divalgb 15755* | Express the division algorithm as stated in divalg 15754 in terms of ∥. (Contributed by Paul Chapman, 31-Mar-2011.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℤ ∧ 𝐷 ≠ 0) → (∃!𝑟 ∈ ℤ ∃𝑞 ∈ ℤ (0 ≤ 𝑟 ∧ 𝑟 < (abs‘𝐷) ∧ 𝑁 = ((𝑞 · 𝐷) + 𝑟)) ↔ ∃!𝑟 ∈ ℕ0 (𝑟 < (abs‘𝐷) ∧ 𝐷 ∥ (𝑁 − 𝑟)))) | ||
Theorem | divalg2 15756* | The division algorithm (theorem) for a positive divisor. (Contributed by Paul Chapman, 21-Mar-2011.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ) → ∃!𝑟 ∈ ℕ0 (𝑟 < 𝐷 ∧ 𝐷 ∥ (𝑁 − 𝑟))) | ||
Theorem | divalgmod 15757 | The result of the mod operator satisfies the requirements for the remainder 𝑅 in the division algorithm for a positive divisor (compare divalg2 15756 and divalgb 15755). This demonstration theorem justifies the use of mod to yield an explicit remainder from this point forward. (Contributed by Paul Chapman, 31-Mar-2011.) (Revised by AV, 21-Aug-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ) → (𝑅 = (𝑁 mod 𝐷) ↔ (𝑅 ∈ ℕ0 ∧ (𝑅 < 𝐷 ∧ 𝐷 ∥ (𝑁 − 𝑅))))) | ||
Theorem | divalgmodcl 15758 | The result of the mod operator satisfies the requirements for the remainder 𝑅 in the division algorithm for a positive divisor. Variant of divalgmod 15757. (Contributed by Stefan O'Rear, 17-Oct-2014.) (Proof shortened by AV, 21-Aug-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ ∧ 𝑅 ∈ ℕ0) → (𝑅 = (𝑁 mod 𝐷) ↔ (𝑅 < 𝐷 ∧ 𝐷 ∥ (𝑁 − 𝑅)))) | ||
Theorem | modremain 15759* | The result of the modulo operation is the remainder of the division algorithm. (Contributed by AV, 19-Aug-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ ∧ (𝑅 ∈ ℕ0 ∧ 𝑅 < 𝐷)) → ((𝑁 mod 𝐷) = 𝑅 ↔ ∃𝑧 ∈ ℤ ((𝑧 · 𝐷) + 𝑅) = 𝑁)) | ||
Theorem | ndvdssub 15760 | Corollary of the division algorithm. If an integer 𝐷 greater than 1 divides 𝑁, then it does not divide any of 𝑁 − 1, 𝑁 − 2... 𝑁 − (𝐷 − 1). (Contributed by Paul Chapman, 31-Mar-2011.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ ∧ (𝐾 ∈ ℕ ∧ 𝐾 < 𝐷)) → (𝐷 ∥ 𝑁 → ¬ 𝐷 ∥ (𝑁 − 𝐾))) | ||
Theorem | ndvdsadd 15761 | Corollary of the division algorithm. If an integer 𝐷 greater than 1 divides 𝑁, then it does not divide any of 𝑁 + 1, 𝑁 + 2... 𝑁 + (𝐷 − 1). (Contributed by Paul Chapman, 31-Mar-2011.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ ∧ (𝐾 ∈ ℕ ∧ 𝐾 < 𝐷)) → (𝐷 ∥ 𝑁 → ¬ 𝐷 ∥ (𝑁 + 𝐾))) | ||
Theorem | ndvdsp1 15762 | Special case of ndvdsadd 15761. If an integer 𝐷 greater than 1 divides 𝑁, it does not divide 𝑁 + 1. (Contributed by Paul Chapman, 31-Mar-2011.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝐷 ∈ ℕ ∧ 1 < 𝐷) → (𝐷 ∥ 𝑁 → ¬ 𝐷 ∥ (𝑁 + 1))) | ||
Theorem | ndvdsi 15763 | A quick test for non-divisibility. (Contributed by Mario Carneiro, 18-Feb-2014.) |
⊢ 𝐴 ∈ ℕ & ⊢ 𝑄 ∈ ℕ0 & ⊢ 𝑅 ∈ ℕ & ⊢ ((𝐴 · 𝑄) + 𝑅) = 𝐵 & ⊢ 𝑅 < 𝐴 ⇒ ⊢ ¬ 𝐴 ∥ 𝐵 | ||
Theorem | flodddiv4 15764 | The floor of an odd integer divided by 4. (Contributed by AV, 17-Jun-2021.) |
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 = ((2 · 𝑀) + 1)) → (⌊‘(𝑁 / 4)) = if(2 ∥ 𝑀, (𝑀 / 2), ((𝑀 − 1) / 2))) | ||
Theorem | fldivndvdslt 15765 | The floor of an integer divided by a nonzero integer not dividing the first integer is less than the integer divided by the positive integer. (Contributed by AV, 4-Jul-2021.) |
⊢ ((𝐾 ∈ ℤ ∧ (𝐿 ∈ ℤ ∧ 𝐿 ≠ 0) ∧ ¬ 𝐿 ∥ 𝐾) → (⌊‘(𝐾 / 𝐿)) < (𝐾 / 𝐿)) | ||
Theorem | flodddiv4lt 15766 | The floor of an odd number divided by 4 is less than the odd number divided by 4. (Contributed by AV, 4-Jul-2021.) |
⊢ ((𝑁 ∈ ℤ ∧ ¬ 2 ∥ 𝑁) → (⌊‘(𝑁 / 4)) < (𝑁 / 4)) | ||
Theorem | flodddiv4t2lthalf 15767 | The floor of an odd number divided by 4, multiplied by 2 is less than the half of the odd number. (Contributed by AV, 4-Jul-2021.) (Proof shortened by AV, 10-Jul-2022.) |
⊢ ((𝑁 ∈ ℤ ∧ ¬ 2 ∥ 𝑁) → ((⌊‘(𝑁 / 4)) · 2) < (𝑁 / 2)) | ||
Syntax | cbits 15768 | Define the binary bits of an integer. |
class bits | ||
Syntax | csad 15769 | Define the sequence addition on bit sequences. |
class sadd | ||
Syntax | csmu 15770 | Define the sequence multiplication on bit sequences. |
class smul | ||
Definition | df-bits 15771* | Define the binary bits of an integer. The expression 𝑀 ∈ (bits‘𝑁) means that the 𝑀-th bit of 𝑁 is 1 (and its negation means the bit is 0). (Contributed by Mario Carneiro, 4-Sep-2016.) |
⊢ bits = (𝑛 ∈ ℤ ↦ {𝑚 ∈ ℕ0 ∣ ¬ 2 ∥ (⌊‘(𝑛 / (2↑𝑚)))}) | ||
Theorem | bitsfval 15772* | Expand the definition of the bits of an integer. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℤ → (bits‘𝑁) = {𝑚 ∈ ℕ0 ∣ ¬ 2 ∥ (⌊‘(𝑁 / (2↑𝑚)))}) | ||
Theorem | bitsval 15773 | Expand the definition of the bits of an integer. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑀 ∈ (bits‘𝑁) ↔ (𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0 ∧ ¬ 2 ∥ (⌊‘(𝑁 / (2↑𝑀))))) | ||
Theorem | bitsval2 15774 | Expand the definition of the bits of an integer. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → (𝑀 ∈ (bits‘𝑁) ↔ ¬ 2 ∥ (⌊‘(𝑁 / (2↑𝑀))))) | ||
Theorem | bitsss 15775 | The set of bits of an integer is a subset of ℕ0. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (bits‘𝑁) ⊆ ℕ0 | ||
Theorem | bitsf 15776 | The bits function is a function from integers to subsets of nonnegative integers. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ bits:ℤ⟶𝒫 ℕ0 | ||
Theorem | bits0 15777 | Value of the zeroth bit. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℤ → (0 ∈ (bits‘𝑁) ↔ ¬ 2 ∥ 𝑁)) | ||
Theorem | bits0e 15778 | The zeroth bit of an even number is zero. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℤ → ¬ 0 ∈ (bits‘(2 · 𝑁))) | ||
Theorem | bits0o 15779 | The zeroth bit of an odd number is zero. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℤ → 0 ∈ (bits‘((2 · 𝑁) + 1))) | ||
Theorem | bitsp1 15780 | The 𝑀 + 1-th bit of 𝑁 is the 𝑀-th bit of ⌊(𝑁 / 2). (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → ((𝑀 + 1) ∈ (bits‘𝑁) ↔ 𝑀 ∈ (bits‘(⌊‘(𝑁 / 2))))) | ||
Theorem | bitsp1e 15781 | The 𝑀 + 1-th bit of 2𝑁 is the 𝑀-th bit of 𝑁. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → ((𝑀 + 1) ∈ (bits‘(2 · 𝑁)) ↔ 𝑀 ∈ (bits‘𝑁))) | ||
Theorem | bitsp1o 15782 | The 𝑀 + 1-th bit of 2𝑁 + 1 is the 𝑀-th bit of 𝑁. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → ((𝑀 + 1) ∈ (bits‘((2 · 𝑁) + 1)) ↔ 𝑀 ∈ (bits‘𝑁))) | ||
Theorem | bitsfzolem 15783* | Lemma for bitsfzo 15784. (Contributed by Mario Carneiro, 5-Sep-2016.) (Revised by AV, 1-Oct-2020.) |
⊢ (𝜑 → 𝑁 ∈ ℕ0) & ⊢ (𝜑 → 𝑀 ∈ ℕ0) & ⊢ (𝜑 → (bits‘𝑁) ⊆ (0..^𝑀)) & ⊢ 𝑆 = inf({𝑛 ∈ ℕ0 ∣ 𝑁 < (2↑𝑛)}, ℝ, < ) ⇒ ⊢ (𝜑 → 𝑁 ∈ (0..^(2↑𝑀))) | ||
Theorem | bitsfzo 15784 | The bits of a number are all less than 𝑀 iff the number is nonnegative and less than 2↑𝑀. (Contributed by Mario Carneiro, 5-Sep-2016.) (Proof shortened by AV, 1-Oct-2020.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → (𝑁 ∈ (0..^(2↑𝑀)) ↔ (bits‘𝑁) ⊆ (0..^𝑀))) | ||
Theorem | bitsmod 15785 | Truncating the bit sequence after some 𝑀 is equivalent to reducing the argument mod 2↑𝑀. (Contributed by Mario Carneiro, 6-Sep-2016.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → (bits‘(𝑁 mod (2↑𝑀))) = ((bits‘𝑁) ∩ (0..^𝑀))) | ||
Theorem | bitsfi 15786 | Every number is associated with a finite set of bits. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℕ0 → (bits‘𝑁) ∈ Fin) | ||
Theorem | bitscmp 15787 | The bit complement of 𝑁 is -𝑁 − 1. (Thus, by bitsfi 15786, all negative numbers have cofinite bits representations.) (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℤ → (ℕ0 ∖ (bits‘𝑁)) = (bits‘(-𝑁 − 1))) | ||
Theorem | 0bits 15788 | The bits of zero. (Contributed by Mario Carneiro, 6-Sep-2016.) |
⊢ (bits‘0) = ∅ | ||
Theorem | m1bits 15789 | The bits of negative one. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (bits‘-1) = ℕ0 | ||
Theorem | bitsinv1lem 15790 | Lemma for bitsinv1 15791. (Contributed by Mario Carneiro, 22-Sep-2016.) |
⊢ ((𝑁 ∈ ℤ ∧ 𝑀 ∈ ℕ0) → (𝑁 mod (2↑(𝑀 + 1))) = ((𝑁 mod (2↑𝑀)) + if(𝑀 ∈ (bits‘𝑁), (2↑𝑀), 0))) | ||
Theorem | bitsinv1 15791* | There is an explicit inverse to the bits function for nonnegative integers (which can be extended to negative integers using bitscmp 15787), part 1. (Contributed by Mario Carneiro, 7-Sep-2016.) |
⊢ (𝑁 ∈ ℕ0 → Σ𝑛 ∈ (bits‘𝑁)(2↑𝑛) = 𝑁) | ||
Theorem | bitsinv2 15792* | There is an explicit inverse to the bits function for nonnegative integers, part 2. (Contributed by Mario Carneiro, 8-Sep-2016.) |
⊢ (𝐴 ∈ (𝒫 ℕ0 ∩ Fin) → (bits‘Σ𝑛 ∈ 𝐴 (2↑𝑛)) = 𝐴) | ||
Theorem | bitsf1ocnv 15793* | The bits function restricted to nonnegative integers is a bijection from the integers to the finite sets of integers. It is in fact the inverse of the Ackermann bijection ackbijnn 15183. (Contributed by Mario Carneiro, 8-Sep-2016.) |
⊢ ((bits ↾ ℕ0):ℕ0–1-1-onto→(𝒫 ℕ0 ∩ Fin) ∧ ◡(bits ↾ ℕ0) = (𝑥 ∈ (𝒫 ℕ0 ∩ Fin) ↦ Σ𝑛 ∈ 𝑥 (2↑𝑛))) | ||
Theorem | bitsf1o 15794 | The bits function restricted to nonnegative integers is a bijection from the integers to the finite sets of integers. It is in fact the inverse of the Ackermann bijection ackbijnn 15183. (Contributed by Mario Carneiro, 8-Sep-2016.) |
⊢ (bits ↾ ℕ0):ℕ0–1-1-onto→(𝒫 ℕ0 ∩ Fin) | ||
Theorem | bitsf1 15795 | The bits function is an injection from ℤ to 𝒫 ℕ0. It is obviously not a bijection (by Cantor's theorem canth2 8670), and in fact its range is the set of finite and cofinite subsets of ℕ0. (Contributed by Mario Carneiro, 22-Sep-2016.) |
⊢ bits:ℤ–1-1→𝒫 ℕ0 | ||
Theorem | 2ebits 15796 | The bits of a power of two. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ (𝑁 ∈ ℕ0 → (bits‘(2↑𝑁)) = {𝑁}) | ||
Theorem | bitsinv 15797* | The inverse of the bits function. (Contributed by Mario Carneiro, 8-Sep-2016.) |
⊢ 𝐾 = ◡(bits ↾ ℕ0) ⇒ ⊢ (𝐴 ∈ (𝒫 ℕ0 ∩ Fin) → (𝐾‘𝐴) = Σ𝑘 ∈ 𝐴 (2↑𝑘)) | ||
Theorem | bitsinvp1 15798 | Recursive definition of the inverse of the bits function. (Contributed by Mario Carneiro, 8-Sep-2016.) |
⊢ 𝐾 = ◡(bits ↾ ℕ0) ⇒ ⊢ ((𝐴 ⊆ ℕ0 ∧ 𝑁 ∈ ℕ0) → (𝐾‘(𝐴 ∩ (0..^(𝑁 + 1)))) = ((𝐾‘(𝐴 ∩ (0..^𝑁))) + if(𝑁 ∈ 𝐴, (2↑𝑁), 0))) | ||
Theorem | sadadd2lem2 15799 | The core of the proof of sadadd2 15809. The intuitive justification for this is that cadd is true if at least two arguments are true, and hadd is true if an odd number of arguments are true, so altogether the result is 𝑛 · 𝐴 where 𝑛 is the number of true arguments, which is equivalently obtained by adding together one 𝐴 for each true argument, on the right side. (Contributed by Mario Carneiro, 8-Sep-2016.) |
⊢ (𝐴 ∈ ℂ → (if(hadd(𝜑, 𝜓, 𝜒), 𝐴, 0) + if(cadd(𝜑, 𝜓, 𝜒), (2 · 𝐴), 0)) = ((if(𝜑, 𝐴, 0) + if(𝜓, 𝐴, 0)) + if(𝜒, 𝐴, 0))) | ||
Definition | df-sad 15800* | Define the addition of two bit sequences, using df-had 1594 and df-cad 1608 bit operations. (Contributed by Mario Carneiro, 5-Sep-2016.) |
⊢ sadd = (𝑥 ∈ 𝒫 ℕ0, 𝑦 ∈ 𝒫 ℕ0 ↦ {𝑘 ∈ ℕ0 ∣ hadd(𝑘 ∈ 𝑥, 𝑘 ∈ 𝑦, ∅ ∈ (seq0((𝑐 ∈ 2o, 𝑚 ∈ ℕ0 ↦ if(cadd(𝑚 ∈ 𝑥, 𝑚 ∈ 𝑦, ∅ ∈ 𝑐), 1o, ∅)), (𝑛 ∈ ℕ0 ↦ if(𝑛 = 0, ∅, (𝑛 − 1))))‘𝑘))}) |
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