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Type | Label | Description |
---|---|---|
Statement | ||
Theorem | 1mhlfehlf 11601 | Prove that 1 - 1/2 = 1/2. (Contributed by David A. Wheeler, 4-Jan-2017.) |
⊢ (1 − (1 / 2)) = (1 / 2) | ||
Theorem | 8th4div3 11602 | An eighth of four thirds is a sixth. (Contributed by Paul Chapman, 24-Nov-2007.) |
⊢ ((1 / 8) · (4 / 3)) = (1 / 6) | ||
Theorem | halfpm6th 11603 | One half plus or minus one sixth. (Contributed by Paul Chapman, 17-Jan-2008.) |
⊢ (((1 / 2) − (1 / 6)) = (1 / 3) ∧ ((1 / 2) + (1 / 6)) = (2 / 3)) | ||
Theorem | it0e0 11604 | i times 0 equals 0. (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ (i · 0) = 0 | ||
Theorem | 2mulicn 11605 | (2 · i) ∈ ℂ. (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ (2 · i) ∈ ℂ | ||
Theorem | 2muline0 11606 | (2 · i) ≠ 0. (Contributed by David A. Wheeler, 8-Dec-2018.) |
⊢ (2 · i) ≠ 0 | ||
Theorem | halfcl 11607 | Closure of half of a number. (Contributed by NM, 1-Jan-2006.) |
⊢ (𝐴 ∈ ℂ → (𝐴 / 2) ∈ ℂ) | ||
Theorem | rehalfcl 11608 | Real closure of half. (Contributed by NM, 1-Jan-2006.) |
⊢ (𝐴 ∈ ℝ → (𝐴 / 2) ∈ ℝ) | ||
Theorem | half0 11609 | Half of a number is zero iff the number is zero. (Contributed by NM, 20-Apr-2006.) |
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) = 0 ↔ 𝐴 = 0)) | ||
Theorem | 2halves 11610 | Two halves make a whole. (Contributed by NM, 11-Apr-2005.) |
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) + (𝐴 / 2)) = 𝐴) | ||
Theorem | halfpos2 11611 | A number is positive iff its half is positive. (Contributed by NM, 10-Apr-2005.) |
⊢ (𝐴 ∈ ℝ → (0 < 𝐴 ↔ 0 < (𝐴 / 2))) | ||
Theorem | halfpos 11612 | A positive number is greater than its half. (Contributed by NM, 28-Oct-2004.) (Proof shortened by Mario Carneiro, 27-May-2016.) |
⊢ (𝐴 ∈ ℝ → (0 < 𝐴 ↔ (𝐴 / 2) < 𝐴)) | ||
Theorem | halfnneg2 11613 | A number is nonnegative iff its half is nonnegative. (Contributed by NM, 9-Dec-2005.) |
⊢ (𝐴 ∈ ℝ → (0 ≤ 𝐴 ↔ 0 ≤ (𝐴 / 2))) | ||
Theorem | halfaddsubcl 11614 | Closure of half-sum and half-difference. (Contributed by Paul Chapman, 12-Oct-2007.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ) → (((𝐴 + 𝐵) / 2) ∈ ℂ ∧ ((𝐴 − 𝐵) / 2) ∈ ℂ)) | ||
Theorem | halfaddsub 11615 | Sum and difference of half-sum and half-difference. (Contributed by Paul Chapman, 12-Oct-2007.) |
⊢ ((𝐴 ∈ ℂ ∧ 𝐵 ∈ ℂ) → ((((𝐴 + 𝐵) / 2) + ((𝐴 − 𝐵) / 2)) = 𝐴 ∧ (((𝐴 + 𝐵) / 2) − ((𝐴 − 𝐵) / 2)) = 𝐵)) | ||
Theorem | subhalfhalf 11616 | Subtracting the half of a number from the number yields the half of the number. (Contributed by AV, 28-Jun-2021.) |
⊢ (𝐴 ∈ ℂ → (𝐴 − (𝐴 / 2)) = (𝐴 / 2)) | ||
Theorem | lt2halves 11617 | A sum is less than the whole if each term is less than half. (Contributed by NM, 13-Dec-2006.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐶 ∈ ℝ) → ((𝐴 < (𝐶 / 2) ∧ 𝐵 < (𝐶 / 2)) → (𝐴 + 𝐵) < 𝐶)) | ||
Theorem | addltmul 11618 | Sum is less than product for numbers greater than 2. (Contributed by Stefan Allan, 24-Sep-2010.) |
⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (2 < 𝐴 ∧ 2 < 𝐵)) → (𝐴 + 𝐵) < (𝐴 · 𝐵)) | ||
Theorem | nominpos 11619* | There is no smallest positive real number. (Contributed by NM, 28-Oct-2004.) |
⊢ ¬ ∃𝑥 ∈ ℝ (0 < 𝑥 ∧ ¬ ∃𝑦 ∈ ℝ (0 < 𝑦 ∧ 𝑦 < 𝑥)) | ||
Theorem | avglt1 11620 | Ordering property for average. (Contributed by Mario Carneiro, 28-May-2014.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ 𝐴 < ((𝐴 + 𝐵) / 2))) | ||
Theorem | avglt2 11621 | Ordering property for average. (Contributed by Mario Carneiro, 28-May-2014.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ ((𝐴 + 𝐵) / 2) < 𝐵)) | ||
Theorem | avgle1 11622 | Ordering property for average. (Contributed by Mario Carneiro, 28-May-2014.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 ≤ 𝐵 ↔ 𝐴 ≤ ((𝐴 + 𝐵) / 2))) | ||
Theorem | avgle2 11623 | Ordering property for average. (Contributed by Jeff Hankins, 15-Sep-2013.) (Revised by Mario Carneiro, 28-May-2014.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 ≤ 𝐵 ↔ ((𝐴 + 𝐵) / 2) ≤ 𝐵)) | ||
Theorem | avgle 11624 | The average of two numbers is less than or equal to at least one of them. (Contributed by NM, 9-Dec-2005.) (Revised by Mario Carneiro, 28-May-2014.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (((𝐴 + 𝐵) / 2) ≤ 𝐴 ∨ ((𝐴 + 𝐵) / 2) ≤ 𝐵)) | ||
Theorem | 2timesd 11625 | Two times a number. (Contributed by Mario Carneiro, 27-May-2016.) |
⊢ (𝜑 → 𝐴 ∈ ℂ) ⇒ ⊢ (𝜑 → (2 · 𝐴) = (𝐴 + 𝐴)) | ||
Theorem | times2d 11626 | A number times 2. (Contributed by Mario Carneiro, 27-May-2016.) |
⊢ (𝜑 → 𝐴 ∈ ℂ) ⇒ ⊢ (𝜑 → (𝐴 · 2) = (𝐴 + 𝐴)) | ||
Theorem | halfcld 11627 | Closure of half of a number (frequently used special case). (Contributed by Mario Carneiro, 27-May-2016.) |
⊢ (𝜑 → 𝐴 ∈ ℂ) ⇒ ⊢ (𝜑 → (𝐴 / 2) ∈ ℂ) | ||
Theorem | 2halvesd 11628 | Two halves make a whole. (Contributed by Mario Carneiro, 27-May-2016.) |
⊢ (𝜑 → 𝐴 ∈ ℂ) ⇒ ⊢ (𝜑 → ((𝐴 / 2) + (𝐴 / 2)) = 𝐴) | ||
Theorem | rehalfcld 11629 | Real closure of half. (Contributed by Mario Carneiro, 27-May-2016.) |
⊢ (𝜑 → 𝐴 ∈ ℝ) ⇒ ⊢ (𝜑 → (𝐴 / 2) ∈ ℝ) | ||
Theorem | lt2halvesd 11630 | A sum is less than the whole if each term is less than half. (Contributed by Mario Carneiro, 27-May-2016.) |
⊢ (𝜑 → 𝐴 ∈ ℝ) & ⊢ (𝜑 → 𝐵 ∈ ℝ) & ⊢ (𝜑 → 𝐶 ∈ ℝ) & ⊢ (𝜑 → 𝐴 < (𝐶 / 2)) & ⊢ (𝜑 → 𝐵 < (𝐶 / 2)) ⇒ ⊢ (𝜑 → (𝐴 + 𝐵) < 𝐶) | ||
Theorem | rehalfcli 11631 | Half a real number is real. Inference form. (Contributed by David Moews, 28-Feb-2017.) |
⊢ 𝐴 ∈ ℝ ⇒ ⊢ (𝐴 / 2) ∈ ℝ | ||
Theorem | lt2addmuld 11632 | If two real numbers are less than a third real number, the sum of the two real numbers is less than twice the third real number. (Contributed by Glauco Siliprandi, 11-Dec-2019.) |
⊢ (𝜑 → 𝐴 ∈ ℝ) & ⊢ (𝜑 → 𝐵 ∈ ℝ) & ⊢ (𝜑 → 𝐶 ∈ ℝ) & ⊢ (𝜑 → 𝐴 < 𝐶) & ⊢ (𝜑 → 𝐵 < 𝐶) ⇒ ⊢ (𝜑 → (𝐴 + 𝐵) < (2 · 𝐶)) | ||
Theorem | add1p1 11633 | Adding two times 1 to a number. (Contributed by AV, 22-Sep-2018.) |
⊢ (𝑁 ∈ ℂ → ((𝑁 + 1) + 1) = (𝑁 + 2)) | ||
Theorem | sub1m1 11634 | Subtracting two times 1 from a number. (Contributed by AV, 23-Oct-2018.) |
⊢ (𝑁 ∈ ℂ → ((𝑁 − 1) − 1) = (𝑁 − 2)) | ||
Theorem | cnm2m1cnm3 11635 | Subtracting 2 and afterwards 1 from a number results in the difference between the number and 3. (Contributed by Alexander van der Vekens, 16-Sep-2018.) |
⊢ (𝐴 ∈ ℂ → ((𝐴 − 2) − 1) = (𝐴 − 3)) | ||
Theorem | xp1d2m1eqxm1d2 11636 | A complex number increased by 1, then divided by 2, then decreased by 1 equals the complex number decreased by 1 and then divided by 2. (Contributed by AV, 24-May-2020.) |
⊢ (𝑋 ∈ ℂ → (((𝑋 + 1) / 2) − 1) = ((𝑋 − 1) / 2)) | ||
Theorem | div4p1lem1div2 11637 | An integer greater than 5, divided by 4 and increased by 1, is less than or equal to the half of the integer minus 1. (Contributed by AV, 8-Jul-2021.) |
⊢ ((𝑁 ∈ ℝ ∧ 6 ≤ 𝑁) → ((𝑁 / 4) + 1) ≤ ((𝑁 − 1) / 2)) | ||
Theorem | nnunb 11638* | The set of positive integers is unbounded above. Theorem I.28 of [Apostol] p. 26. (Contributed by NM, 21-Jan-1997.) |
⊢ ¬ ∃𝑥 ∈ ℝ ∀𝑦 ∈ ℕ (𝑦 < 𝑥 ∨ 𝑦 = 𝑥) | ||
Theorem | arch 11639* | Archimedean property of real numbers. For any real number, there is an integer greater than it. Theorem I.29 of [Apostol] p. 26. (Contributed by NM, 21-Jan-1997.) |
⊢ (𝐴 ∈ ℝ → ∃𝑛 ∈ ℕ 𝐴 < 𝑛) | ||
Theorem | nnrecl 11640* | There exists a positive integer whose reciprocal is less than a given positive real. Exercise 3 of [Apostol] p. 28. (Contributed by NM, 8-Nov-2004.) |
⊢ ((𝐴 ∈ ℝ ∧ 0 < 𝐴) → ∃𝑛 ∈ ℕ (1 / 𝑛) < 𝐴) | ||
Theorem | bndndx 11641* | A bounded real sequence 𝐴(𝑘) is less than or equal to at least one of its indices. (Contributed by NM, 18-Jan-2008.) |
⊢ (∃𝑥 ∈ ℝ ∀𝑘 ∈ ℕ (𝐴 ∈ ℝ ∧ 𝐴 ≤ 𝑥) → ∃𝑘 ∈ ℕ 𝐴 ≤ 𝑘) | ||
Syntax | cn0 11642 | Extend class notation to include the class of nonnegative integers. |
class ℕ0 | ||
Definition | df-n0 11643 | Define the set of nonnegative integers. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ ℕ0 = (ℕ ∪ {0}) | ||
Theorem | elnn0 11644 | Nonnegative integers expressed in terms of naturals and zero. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ (𝐴 ∈ ℕ0 ↔ (𝐴 ∈ ℕ ∨ 𝐴 = 0)) | ||
Theorem | nnssnn0 11645 | Positive naturals are a subset of nonnegative integers. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ ℕ ⊆ ℕ0 | ||
Theorem | nn0ssre 11646 | Nonnegative integers are a subset of the reals. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ ℕ0 ⊆ ℝ | ||
Theorem | nn0sscn 11647 | Nonnegative integers are a subset of the complex numbers. (Contributed by NM, 9-May-2004.) Reduce dependencies on axioms. (Revised by Steven Nguyen, 8-Oct-2022.) |
⊢ ℕ0 ⊆ ℂ | ||
Theorem | nn0sscnOLD 11648 | Obsolete version of nn0sscn 11647 as of 8-Oct-2022. Nonnegative integers are a subset of the complex numbers. (Contributed by NM, 9-May-2004.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ ℕ0 ⊆ ℂ | ||
Theorem | nn0ex 11649 | The set of nonnegative integers exists. (Contributed by NM, 18-Jul-2004.) |
⊢ ℕ0 ∈ V | ||
Theorem | nnnn0 11650 | A positive integer is a nonnegative integer. (Contributed by NM, 9-May-2004.) |
⊢ (𝐴 ∈ ℕ → 𝐴 ∈ ℕ0) | ||
Theorem | nnnn0i 11651 | A positive integer is a nonnegative integer. (Contributed by NM, 20-Jun-2005.) |
⊢ 𝑁 ∈ ℕ ⇒ ⊢ 𝑁 ∈ ℕ0 | ||
Theorem | nn0re 11652 | A nonnegative integer is a real number. (Contributed by NM, 9-May-2004.) |
⊢ (𝐴 ∈ ℕ0 → 𝐴 ∈ ℝ) | ||
Theorem | nn0cn 11653 | A nonnegative integer is a complex number. (Contributed by NM, 9-May-2004.) |
⊢ (𝐴 ∈ ℕ0 → 𝐴 ∈ ℂ) | ||
Theorem | nn0rei 11654 | A nonnegative integer is a real number. (Contributed by NM, 14-May-2003.) |
⊢ 𝐴 ∈ ℕ0 ⇒ ⊢ 𝐴 ∈ ℝ | ||
Theorem | nn0cni 11655 | A nonnegative integer is a complex number. (Contributed by NM, 14-May-2003.) Reduce dependencies on axioms. (Revised by Steven Nguyen, 8-Oct-2022.) |
⊢ 𝐴 ∈ ℕ0 ⇒ ⊢ 𝐴 ∈ ℂ | ||
Theorem | nn0cniOLD 11656 | Obsolete version of nn0cni 11655 as of 8-Oct-2022. A nonnegative integer is a complex number. (Contributed by NM, 14-May-2003.) (Proof modification is discouraged.) (New usage is discouraged.) |
⊢ 𝐴 ∈ ℕ0 ⇒ ⊢ 𝐴 ∈ ℂ | ||
Theorem | dfn2 11657 | The set of positive integers defined in terms of nonnegative integers. (Contributed by NM, 23-Sep-2007.) (Proof shortened by Mario Carneiro, 13-Feb-2013.) |
⊢ ℕ = (ℕ0 ∖ {0}) | ||
Theorem | elnnne0 11658 | The positive integer property expressed in terms of difference from zero. (Contributed by Stefan O'Rear, 12-Sep-2015.) |
⊢ (𝑁 ∈ ℕ ↔ (𝑁 ∈ ℕ0 ∧ 𝑁 ≠ 0)) | ||
Theorem | 0nn0 11659 | 0 is a nonnegative integer. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 0 ∈ ℕ0 | ||
Theorem | 1nn0 11660 | 1 is a nonnegative integer. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 1 ∈ ℕ0 | ||
Theorem | 2nn0 11661 | 2 is a nonnegative integer. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 2 ∈ ℕ0 | ||
Theorem | 3nn0 11662 | 3 is a nonnegative integer. (Contributed by Mario Carneiro, 18-Feb-2014.) |
⊢ 3 ∈ ℕ0 | ||
Theorem | 4nn0 11663 | 4 is a nonnegative integer. (Contributed by Mario Carneiro, 18-Feb-2014.) |
⊢ 4 ∈ ℕ0 | ||
Theorem | 5nn0 11664 | 5 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015.) |
⊢ 5 ∈ ℕ0 | ||
Theorem | 6nn0 11665 | 6 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015.) |
⊢ 6 ∈ ℕ0 | ||
Theorem | 7nn0 11666 | 7 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015.) |
⊢ 7 ∈ ℕ0 | ||
Theorem | 8nn0 11667 | 8 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015.) |
⊢ 8 ∈ ℕ0 | ||
Theorem | 9nn0 11668 | 9 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015.) |
⊢ 9 ∈ ℕ0 | ||
Theorem | nn0ge0 11669 | A nonnegative integer is greater than or equal to zero. (Contributed by NM, 9-May-2004.) (Revised by Mario Carneiro, 16-May-2014.) |
⊢ (𝑁 ∈ ℕ0 → 0 ≤ 𝑁) | ||
Theorem | nn0nlt0 11670 | A nonnegative integer is not less than zero. (Contributed by NM, 9-May-2004.) (Revised by Mario Carneiro, 27-May-2016.) |
⊢ (𝐴 ∈ ℕ0 → ¬ 𝐴 < 0) | ||
Theorem | nn0ge0i 11671 | Nonnegative integers are nonnegative. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ 0 ≤ 𝑁 | ||
Theorem | nn0le0eq0 11672 | A nonnegative integer is less than or equal to zero iff it is equal to zero. (Contributed by NM, 9-Dec-2005.) |
⊢ (𝑁 ∈ ℕ0 → (𝑁 ≤ 0 ↔ 𝑁 = 0)) | ||
Theorem | nn0p1gt0 11673 | A nonnegative integer increased by 1 is greater than 0. (Contributed by Alexander van der Vekens, 3-Oct-2018.) |
⊢ (𝑁 ∈ ℕ0 → 0 < (𝑁 + 1)) | ||
Theorem | nnnn0addcl 11674 | A positive integer plus a nonnegative integer is a positive integer. (Contributed by NM, 20-Apr-2005.) (Proof shortened by Mario Carneiro, 16-May-2014.) |
⊢ ((𝑀 ∈ ℕ ∧ 𝑁 ∈ ℕ0) → (𝑀 + 𝑁) ∈ ℕ) | ||
Theorem | nn0nnaddcl 11675 | A nonnegative integer plus a positive integer is a positive integer. (Contributed by NM, 22-Dec-2005.) |
⊢ ((𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ) → (𝑀 + 𝑁) ∈ ℕ) | ||
Theorem | 0mnnnnn0 11676 | The result of subtracting a positive integer from 0 is not a nonnegative integer. (Contributed by Alexander van der Vekens, 19-Mar-2018.) |
⊢ (𝑁 ∈ ℕ → (0 − 𝑁) ∉ ℕ0) | ||
Theorem | un0addcl 11677 | If 𝑆 is closed under addition, then so is 𝑆 ∪ {0}. (Contributed by Mario Carneiro, 17-Jul-2014.) |
⊢ (𝜑 → 𝑆 ⊆ ℂ) & ⊢ 𝑇 = (𝑆 ∪ {0}) & ⊢ ((𝜑 ∧ (𝑀 ∈ 𝑆 ∧ 𝑁 ∈ 𝑆)) → (𝑀 + 𝑁) ∈ 𝑆) ⇒ ⊢ ((𝜑 ∧ (𝑀 ∈ 𝑇 ∧ 𝑁 ∈ 𝑇)) → (𝑀 + 𝑁) ∈ 𝑇) | ||
Theorem | un0mulcl 11678 | If 𝑆 is closed under multiplication, then so is 𝑆 ∪ {0}. (Contributed by Mario Carneiro, 17-Jul-2014.) |
⊢ (𝜑 → 𝑆 ⊆ ℂ) & ⊢ 𝑇 = (𝑆 ∪ {0}) & ⊢ ((𝜑 ∧ (𝑀 ∈ 𝑆 ∧ 𝑁 ∈ 𝑆)) → (𝑀 · 𝑁) ∈ 𝑆) ⇒ ⊢ ((𝜑 ∧ (𝑀 ∈ 𝑇 ∧ 𝑁 ∈ 𝑇)) → (𝑀 · 𝑁) ∈ 𝑇) | ||
Theorem | nn0addcl 11679 | Closure of addition of nonnegative integers. (Contributed by Raph Levien, 10-Dec-2002.) (Proof shortened by Mario Carneiro, 17-Jul-2014.) |
⊢ ((𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0) → (𝑀 + 𝑁) ∈ ℕ0) | ||
Theorem | nn0mulcl 11680 | Closure of multiplication of nonnegative integers. (Contributed by NM, 22-Jul-2004.) (Proof shortened by Mario Carneiro, 17-Jul-2014.) |
⊢ ((𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0) → (𝑀 · 𝑁) ∈ ℕ0) | ||
Theorem | nn0addcli 11681 | Closure of addition of nonnegative integers, inference form. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 𝑀 ∈ ℕ0 & ⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ (𝑀 + 𝑁) ∈ ℕ0 | ||
Theorem | nn0mulcli 11682 | Closure of multiplication of nonnegative integers, inference form. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 𝑀 ∈ ℕ0 & ⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ (𝑀 · 𝑁) ∈ ℕ0 | ||
Theorem | nn0p1nn 11683 | A nonnegative integer plus 1 is a positive integer. Strengthening of peano2nn 11388. (Contributed by Raph Levien, 30-Jun-2006.) (Revised by Mario Carneiro, 16-May-2014.) |
⊢ (𝑁 ∈ ℕ0 → (𝑁 + 1) ∈ ℕ) | ||
Theorem | peano2nn0 11684 | Second Peano postulate for nonnegative integers. (Contributed by NM, 9-May-2004.) |
⊢ (𝑁 ∈ ℕ0 → (𝑁 + 1) ∈ ℕ0) | ||
Theorem | nnm1nn0 11685 | A positive integer minus 1 is a nonnegative integer. (Contributed by Jason Orendorff, 24-Jan-2007.) (Revised by Mario Carneiro, 16-May-2014.) |
⊢ (𝑁 ∈ ℕ → (𝑁 − 1) ∈ ℕ0) | ||
Theorem | elnn0nn 11686 | The nonnegative integer property expressed in terms of positive integers. (Contributed by NM, 10-May-2004.) (Proof shortened by Mario Carneiro, 16-May-2014.) |
⊢ (𝑁 ∈ ℕ0 ↔ (𝑁 ∈ ℂ ∧ (𝑁 + 1) ∈ ℕ)) | ||
Theorem | elnnnn0 11687 | The positive integer property expressed in terms of nonnegative integers. (Contributed by NM, 10-May-2004.) |
⊢ (𝑁 ∈ ℕ ↔ (𝑁 ∈ ℂ ∧ (𝑁 − 1) ∈ ℕ0)) | ||
Theorem | elnnnn0b 11688 | The positive integer property expressed in terms of nonnegative integers. (Contributed by NM, 1-Sep-2005.) |
⊢ (𝑁 ∈ ℕ ↔ (𝑁 ∈ ℕ0 ∧ 0 < 𝑁)) | ||
Theorem | elnnnn0c 11689 | The positive integer property expressed in terms of nonnegative integers. (Contributed by NM, 10-Jan-2006.) |
⊢ (𝑁 ∈ ℕ ↔ (𝑁 ∈ ℕ0 ∧ 1 ≤ 𝑁)) | ||
Theorem | nn0addge1 11690 | A number is less than or equal to itself plus a nonnegative integer. (Contributed by NM, 10-Mar-2005.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝑁 ∈ ℕ0) → 𝐴 ≤ (𝐴 + 𝑁)) | ||
Theorem | nn0addge2 11691 | A number is less than or equal to itself plus a nonnegative integer. (Contributed by NM, 10-Mar-2005.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝑁 ∈ ℕ0) → 𝐴 ≤ (𝑁 + 𝐴)) | ||
Theorem | nn0addge1i 11692 | A number is less than or equal to itself plus a nonnegative integer. (Contributed by NM, 10-Mar-2005.) |
⊢ 𝐴 ∈ ℝ & ⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ 𝐴 ≤ (𝐴 + 𝑁) | ||
Theorem | nn0addge2i 11693 | A number is less than or equal to itself plus a nonnegative integer. (Contributed by NM, 10-Mar-2005.) |
⊢ 𝐴 ∈ ℝ & ⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ 𝐴 ≤ (𝑁 + 𝐴) | ||
Theorem | nn0sub 11694 | Subtraction of nonnegative integers. (Contributed by NM, 9-May-2004.) (Proof shortened by Mario Carneiro, 16-May-2014.) |
⊢ ((𝑀 ∈ ℕ0 ∧ 𝑁 ∈ ℕ0) → (𝑀 ≤ 𝑁 ↔ (𝑁 − 𝑀) ∈ ℕ0)) | ||
Theorem | ltsubnn0 11695 | Subtracting a nonnegative integer from a nonnegative integer which is greater than the first one results in a nonnegative integer. (Contributed by Alexander van der Vekens, 6-Apr-2018.) |
⊢ ((𝐴 ∈ ℕ0 ∧ 𝐵 ∈ ℕ0) → (𝐵 < 𝐴 → (𝐴 − 𝐵) ∈ ℕ0)) | ||
Theorem | nn0negleid 11696 | A nonnegative integer is greater than or equal to its negative. (Contributed by AV, 13-Aug-2021.) |
⊢ (𝐴 ∈ ℕ0 → -𝐴 ≤ 𝐴) | ||
Theorem | difgtsumgt 11697 | If the difference of a real number and a nonnegative integer is greater than another real number, the sum of the real number and the nonnegative integer is also greater than the other real number. (Contributed by AV, 13-Aug-2021.) |
⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℕ0 ∧ 𝐶 ∈ ℝ) → (𝐶 < (𝐴 − 𝐵) → 𝐶 < (𝐴 + 𝐵))) | ||
Theorem | nn0le2xi 11698 | A nonnegative integer is less than or equal to twice itself. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ 𝑁 ≤ (2 · 𝑁) | ||
Theorem | nn0lele2xi 11699 | 'Less than or equal to' implies 'less than or equal to twice' for nonnegative integers. (Contributed by Raph Levien, 10-Dec-2002.) |
⊢ 𝑀 ∈ ℕ0 & ⊢ 𝑁 ∈ ℕ0 ⇒ ⊢ (𝑁 ≤ 𝑀 → 𝑁 ≤ (2 · 𝑀)) | ||
Theorem | frnnn0supp 11700 | Two ways to write the support of a function on ℕ0. (Contributed by Mario Carneiro, 29-Dec-2014.) (Revised by AV, 7-Jul-2019.) |
⊢ ((𝐼 ∈ 𝑉 ∧ 𝐹:𝐼⟶ℕ0) → (𝐹 supp 0) = (◡𝐹 “ ℕ)) |
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