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Mathematical proof

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computer-assisted proof can be reduced by incorporating redundancy and self-checks into calculations, and by developing multiple independent approaches and programs. Errors can never be completely ruled out in case of verification of a proof by humans either, especially if the proof contains natural language and requires deep mathematical insight to uncover the potential hidden assumptions and fallacies involved.
33: 3760: 2506: 5959: 2758: 3505:...brought home again to Benoit that there was a 'mathematics of the eye', that visualization of a problem was as valid a method as any for finding a solution. Amazingly, he found himself alone with this conjecture. The teaching of mathematics in France was dominated by a handful of dogmatic mathematicians hiding behind the pseudonym 'Bourbaki'... 2471:, can be constructed in a way which appear to prove a supposed mathematical fact but only do so by neglecting tiny errors (for example, supposedly straight lines which actually bend slightly) which are unnoticeable until the entire picture is closely examined, with lengths and angles precisely measured or calculated. 3446:
What to do with the pictures? Two thoughts surfaced: the first was that they were unpublishable in the standard way, there were no theorems only very suggestive pictures. They furnished convincing evidence for many conjectures and lures to further exploration, but theorems were coins of the realm and
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in elementary geometry classes in the United States. The proof is written as a series of lines in two columns. In each line, the left-hand column contains a proposition, while the right-hand column contains a brief explanation of how the corresponding proposition in the left-hand column is either an
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In the probabilistic method, one seeks an object having a given property, starting with a large set of candidates. One assigns a certain probability for each candidate to be chosen, and then proves that there is a non-zero probability that a chosen candidate will have the desired property. This does
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intended to convince the audience of the truth of a statement. The standard of rigor is not absolute and has varied throughout history. A proof can be presented differently depending on the intended audience. To gain acceptance, a proof has to meet communal standards of rigor; an argument considered
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Until the twentieth century it was assumed that any proof could, in principle, be checked by a competent mathematician to confirm its validity. However, computers are now used both to prove theorems and to carry out calculations that are too long for any human or team of humans to check; the first
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with a certain property exists—without explaining how such an object can be found. Often, this takes the form of a proof by contradiction in which the nonexistence of the object is proved to be impossible. In contrast, a constructive proof establishes that a particular object exists by providing a
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have attempted to formulate philosophical arguments in an axiomatic manner, whereby mathematical proof standards could be applied to argumentation in general philosophy. Other mathematician-philosophers have tried to use standards of mathematical proof and reason, without empiricism, to arrive at
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is an example of a computer-assisted proof. Some mathematicians are concerned that the possibility of an error in a computer program or a run-time error in its calculations calls the validity of such computer-assisted proofs into question. In practice, the chances of an error invalidating a
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The definition of a formal proof is intended to capture the concept of proofs as written in the practice of mathematics. The soundness of this definition amounts to the belief that a published proof can, in principle, be converted into a formal proof. However, outside the field of automated
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A statement whose truth is either to be taken as self-evident or to be assumed. Certain areas of mathematics involve choosing a set of axioms and discovering what results can be derived from them, providing proofs for the theorems that are
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In proof by exhaustion, the conclusion is established by dividing it into a finite number of cases and proving each one separately. The number of cases sometimes can become very large. For example, the first proof of the
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worked with numbers as such, called "lines" but not necessarily considered as measurements of geometric objects, to prove algebraic propositions concerning multiplication, division, etc., including the existence of
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Mandelbrot, working at the IBM Research Laboratory, did some computer simulations for these sets on the reasonable assumption that, if you wanted to prove something, it might be helpful to know the answer ahead of
3187:: "The study of Proof Theory is traditionally motivated by the problem of formalizing mathematical proofs; the original formulation of first-order logic by Frege was the first successful step in this direction." 368:
in a formal language, starting with an assumption, and with each subsequent formula a logical consequence of the preceding ones. This definition makes the concept of proof amenable to study. Indeed, the field of
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from which probability statements are derived require empirical evidence from outside mathematics to verify. In physics, in addition to statistical methods, "statistical proof" can refer to the specialized
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Plausibility arguments using heuristic devices such as pictures and analogies preceded strict mathematical proof. It is likely that the idea of demonstrating a conclusion first arose in connection with
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developments of the late 19th and 20th centuries, proofs were an essential part of mathematics. With the increase in computing power in the 1960s, significant work began to be done investigating
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was known for describing proofs which he found to be particularly elegant as coming from "The Book", a hypothetical tome containing the most beautiful method(s) of proving each theorem. The book
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axiom, a hypothesis, or can be logically derived from previous propositions. The left-hand column is typically headed "Statements" and the right-hand column is typically headed "Reasons".
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In direct proof, the conclusion is established by logically combining the axioms, definitions, and earlier theorems. For example, direct proof can be used to prove that the sum of two
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which establish "reasonable expectation". Presenting many cases in which the statement holds is not enough for a proof, which must demonstrate that the statement is true in
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was a proof by exhaustion with 1,936 cases. This proof was controversial because the majority of the cases were checked by a computer program, not by hand.
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Proof by construction, or proof by example, is the construction of a concrete example with a property to show that something having that property exists.
3912: 188:(to try). The legal term "probity" means authority or credibility, the power of testimony to prove facts when given by persons of reputation or status. 3776: 2160: 2393:. Early pioneers of these methods intended the work ultimately to be resolved into a classical proof-theorem framework, e.g. the early development of 249:, was read by anyone who was considered educated in the West until the middle of the 20th century. In addition to theorems of geometry, such as the 2283: 2497:, could only be proved using "higher" mathematics. However, over time, many of these results have been reproved using only elementary techniques. 562:
the next case. Since in principle the induction rule can be applied repeatedly (starting from the proved base case), it follows that all (usually
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A combinatorial proof establishes the equivalence of different expressions by showing that they count the same object in different ways. Often a
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A probabilistic proof is not to be confused with an argument that a theorem is 'probably' true, a 'plausibility argument'. The work toward the
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studies formal proofs and their properties, the most famous and surprising being that almost all axiomatic systems can generate certain
3255: 4984: 3519:"Establishing a Custom of Proving in American School Geometry: Evolution of the Two-Column Proof in the Early Twentieth Century" 196:, which originated in practical problems of land measurement. The development of mathematical proof is primarily the product of 1356:. Since the expression on the left is an integer multiple of 2, the right expression is by definition divisible by 2. That is, 577:
A common application of proof by mathematical induction is to prove that a property known to hold for one number holds for all
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The Emergence of Probability: A Philosophical Study of Early Ideas about Probability, Induction and Statistical Inference
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many) cases are provable. This avoids having to prove each case individually. A variant of mathematical induction is
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provides two different expressions for the size of a single set, again showing that the two expressions are equal.
220:(384–322 BCE) said definitions should describe the concept being defined in terms of other concepts already known. 49:, a textbook used for millennia to teach proof-writing techniques. The diagram accompanies Book II, Proposition 5. 5569: 4540: 4233: 2567: 2526:
The expression "mathematical proof" is used by lay people to refer to using mathematical methods or arguing with
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Psychologism views mathematical proofs as psychological or mental objects. Mathematician philosophers, such as
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not specify which candidates have the property, but the probability could not be positive without at least one.
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have variously criticized this view and attempted to develop a semantics for what they considered to be the
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mathematical proof to establish theorems in statistics, it is usually not a mathematical proof in that the
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method of finding it. The following famous example of a nonconstructive proof shows that there exist two
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An elementary proof is a proof which only uses basic techniques. More specifically, the term is used in
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A probabilistic proof is one in which an example is shown to exist, with certainty, by using methods of
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Matvievskaya, Galina (1987), "The Theory of Quadratic Irrationals in Medieval Oriental Mathematics",
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Although not a formal proof, a visual demonstration of a mathematical theorem is sometimes called a "
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which usually admits some ambiguity. In most mathematical literature, proofs are written in terms of
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The shorter phrase "proof by induction" is often used instead of "proof by mathematical induction".
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Mathematicians have shown there are many statements that are neither provable nor disprovable in
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Mathematik für das Bachelorstudium I: Grundlagen und Grundzüge der linearen Algebra und Analysis
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possible cases. A proposition that has not been proved but is believed to be true is known as a
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guarantee the conclusion. The argument may use other previously established statements, such as
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Mathematics for the Bachelor's degree I: Fundamentals and basics of linear algebra and analysis
3172:, Studies in Logic and the Foundations of Mathematics, vol. 137, Elsevier, pp. 1–78, 2732: 2618: 2349:(ZFC), the standard system of set theory in mathematics (assuming that ZFC is consistent); see 2291: 1538: 1195: 545: 333: 298: 294: 36: 6019: 5939: 5406: 5259: 5051: 4769: 4505: 4411: 4270: 4255: 4136: 4111: 3637:"What Do Mathematicians Want? Probabilistic Proofs and the Epistemic Goals of Mathematicians" 3058:"The genesis of proof in ancient Greece The pedagogical implications of a Husserlian reading" 2816: 2811: 2514: 2468: 1869: 1499: 1489: 533: 529: 390: 176:(to test). Related modern words are English "probe", "probation", and "probability", Spanish 147: 139: 3184: 2233: 1675: 1416:
are both even, they have 2 as a common factor. This contradicts our previous statement that
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Davis, Philip J. (1972), "Fidelity in Mathematical Discourse: Is One and One Really Two?"
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shows that many axiom systems of mathematical interest will have undecidable statements.
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A closed chain inference shows that a collection of statements are pairwise equivalent.
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The expression "statistical proof" may be used technically or colloquially in areas of
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A particular way of organising a proof using two parallel columns is often used as a
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is used to show that the expressions for their two sizes are equal. Alternatively, a
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occurs, hence the statement must be false. A famous example involves the proof that
929: 290: 266: 209: 197: 150:, oral traditions in the mainstream mathematical community or in other cultures. The 104:, or a hypothesis if frequently used as an assumption for further mathematical work. 3557: 1206:(by reduction to the absurd), it is shown that if some statement is assumed true, a 5868: 5594: 5589: 5486: 5481: 5374: 5331: 5153: 5114: 5109: 5094: 4920: 4877: 4774: 4572: 4522: 4096: 4058: 3694: 3616: 3611: 3543: 3535: 3136: 2572: 2490: 2480: 2394: 2275: 1503: 1495: 310: 228: 167: 112: 2223:{\displaystyle \left({\sqrt {2}}^{\sqrt {2}}\right)^{\sqrt {2}}={\sqrt {2}}^{2}=2} 5714: 5656: 5467: 5457: 5411: 5394: 5349: 5311: 5213: 5133: 4940: 4867: 4840: 4828: 4734: 4648: 4622: 4577: 4545: 4346: 4148: 4091: 4041: 4006: 3964: 3770: 3417: 3391: 3320: 3289: 3262: 2696: 2606: 2596: 2435: 1918: 382: 361: 240: 3732: 3657: 3601: 1807:. Probabilistic proof, like proof by construction, is one of many ways to prove 5968: 5661: 5640: 5555: 5452: 5431: 5389: 5369: 5264: 5119: 4717: 4707: 4697: 4692: 4626: 4500: 4376: 4265: 4260: 4238: 3839: 2912: 2414:". The left-hand picture below is an example of a historic visual proof of the 1831: 1507: 944: 921: 578: 325: 232: 119: 3539: 3463: 2677: 2587:, when the data or diagram is adequately convincing without further analysis. 1822:
shows how far plausibility is from genuine proof, as does the disproof of the
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For example, we can prove by induction that all positive integers of the form
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and, by definition, is even. Hence, the sum of any two even integers is even.
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How to Read and Do Proofs: An Introduction to Mathematical Thought Processes
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For example, contraposition can be used to establish that, given an integer
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the conventions of that day dictated that journals only published theorems.
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Examples of simple proofs by mathematical induction for all natural numbers
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This proof uses the definition of even integers, the integer properties of
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As practiced, a proof is expressed in natural language and is a rigorous
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is written to indicate the end of a proof. This abbreviation stands for
5786: 5754: 5719: 4366: 4221: 4192: 3998: 2544:"Statistical proof" from data refers to the application of statistics, 2338:, which is neither provable nor refutable from the remaining axioms of 285: 101: 5848: 5709: 5620: 5518: 5421: 4474: 4391: 4351: 4315: 4251: 4063: 4053: 4026: 3789: 3636: 2692: 2688: 2614: 2362: 1849: 1510:
to disprove a proposition that all elements have a certain property.
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The Nuts and Bolts of Proofs: An Introduction to Mathematical Proofs
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are each pairwise equivalent, proofs are given for the implications
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is also an integer. Substitution into the original equation yields 2
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were a rational number. Then it could be written in lowest terms as
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Fallis, Don (1997), "The Epistemic Status of Probabilistic Proof."
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Animated visual proof for the Pythagorean theorem by rearrangement.
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A statement that is neither provable nor disprovable from a set of
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Mathematics for Computer Scientists: Fundamentals and Applications
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The pairwise equivalence of the statements then results from the
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is concerned with the role of language and logic in proofs, and
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An Introduction to the History of Mathematics (Saunders Series)
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Moutsios-Rentzos, Andreas; Spyrou, Panagiotis (February 2015).
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is irrational (this is true, but the proof is not elementary).
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without the involvement of natural language, are considered in
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is called undecidable (from those axioms). One example is the
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instead of natural language. A formal proof is a sequence of
236: 108: 77: 69: 3265:, University of Warwick Glossary of Mathematical Terminology 2887:
The Concise Oxford Dictionary of Mathematics, Fourth edition
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which establish logical certainty, to be distinguished from
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Influence of mathematical proof methods outside mathematics
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In proof by contradiction, also known by the Latin phrase
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of propositions deduced in a mathematical proof, such as
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be a mathematical statement involving the natural number
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Struckmann, Werner; Wätjen, Dietmar (October 20, 2016).
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must also be even, as seen in the proposition above (in
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Despite its name, mathematical induction is a method of
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Mathematik für Informatiker: Grundlagen und Anwendungen
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No work, except The Bible, has been more widely used...
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Proofs in Mathematics: Simple, Charming and Fallacious
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Plaue, Matthias; Scherfner, Mike (February 11, 2019).
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has led to much examination of current and historical
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is odd. The product of two odd numbers is odd, hence
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Proof and Other Dilemmas: Mathematics and Philosophy
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Zermelo–Fraenkel set theory with the axiom of choice
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A second animated proof of the Pythagorean theorem.
352:The concept of proof is formalized in the field of 3482: 3276:Four color theorem#Simplification and verification 2687:statements outside of mathematics, but having the 2363:Heuristic mathematics and experimental mathematics 2252: 2222: 2149: 2119: 2080: 2047: 2011: 1974: 1937: 1909: 1770: 1730: 1684: 1664: 1624: 1584: 1468: 1440: 1340: 1295: 1258: 1226: 1177: 1154: 1127: 1100: 1061: 1041: 1017: 997: 970: 539: 1585:{\displaystyle \varphi _{1},\ldots ,\varphi _{n}} 5996: 3329:] (in German). Springer-Verlag. p. 28. 3318: 3298:] (in German). Springer-Verlag. p. 26. 2434:Visual proof for the (3,4,5) triangle as in the 1424:have no common factor, so we must conclude that 832:to an odd number results in an odd number. But 2864:"One of the Oldest Extant Diagrams from Euclid" 2533: 570:, which can be used, for example, to prove the 3480: 3287: 3164:(1998), "An introduction to proof theory", in 2617:. Inductive logic should not be confused with 2230:, which is thus a rational number of the form 1834:) are as good as genuine mathematical proofs. 464:. Since they are even, they can be written as 111:expressed in mathematical symbols, along with 5563: 3805: 3652: 3012:The History and Concept of Mathematical Proof 2956:Definition 3.1. Proof: An Informal Definition 3570: 3116: 3023: 2591:Inductive logic proofs and Bayesian analysis 1945:is irrational (an easy proof is known since 1365: 2897: 2639: 2305: 2019:is a rational number and we are done (take 1874:A nonconstructive proof establishes that a 838: − 1) + 2 = 2 532:under addition and multiplication, and the 269:and a proof that there are infinitely many 39:, one of the oldest surviving fragments of 5570: 5556: 3997: 3812: 3798: 3206:Universität Zürich – Theologische Fakultät 3120:Annals of the New York Academy of Sciences 2858: 915: 3615: 3547: 3427:Indra's Pearls: The Vision of Felix Klein 2903: 2467:Some illusory visual proofs, such as the 2325: 2120:{\displaystyle a={\sqrt {2}}^{\sqrt {2}}} 1532: 1189: 588:} be the set of natural numbers, and let 223:Mathematical proof was revolutionized by 3711: 3007: 3005: 2504: 1863: 1498:, for instance, proved the existence of 1483: 1165:even, the supposition must be false, so 409:" that such a distinction is untenable. 200:, and one of its greatest achievements. 161: 31: 3730: 3014:, Steven G. Krantz. 1. February 5, 2007 2976: 2935: 2489:to refer to proofs that make no use of 2389:beyond the proof-theorem framework, in 2081:{\displaystyle {\sqrt {2}}^{\sqrt {2}}} 2012:{\displaystyle {\sqrt {2}}^{\sqrt {2}}} 1975:{\displaystyle {\sqrt {2}}^{\sqrt {2}}} 1296:{\displaystyle {\sqrt {2}}={a \over b}} 774:is odd, since it leaves a remainder of 572:irrationality of the square root of two 14: 5997: 3819: 3714:How to Prove It: A Structured Approach 3634: 3573:"Introduction to the Two-Column Proof" 3516: 2522:Colloquial use of "mathematical proof" 2357:Gödel's (first) incompleteness theorem 2264:Statistical proofs in pure mathematics 1837: 1792: 1546:In order to prove that the statements 1513: 1506:. It can also be used to construct a 172:The word "proof" comes from the Latin 68:, showing that the stated assumptions 5551: 3793: 3688: 3659:Proof in Mathematics: An Introduction 3600: 3196: 3002: 2351:List of statements undecidable in ZFC 349:vague or incomplete may be rejected. 339: 324:treats proofs as inductively defined 27:Reasoning for mathematical statements 3160: 3081: 2552:to infer propositions regarding the 2509:A two-column proof published in 1913 2397:, which was ultimately so resolved. 276:Further advances also took place in 84:. Proofs are examples of exhaustive 5745:Analytic and synthetic propositions 5616:Formal semantics (natural language) 3607:Mathematics and Plausible Reasoning 3460:"A Note on the History of Fractals" 2729:"that which was to be demonstrated" 2682:Philosopher-mathematicians such as 2500: 2474: 2400: 2373:While early mathematicians such as 429: 231:still in use today. It starts with 80:, along with the accepted rules of 24: 3594: 3527:Educational Studies in Mathematics 3141:10.1111/j.1749-6632.1987.tb37206.x 2885:Clapham, C. & Nicholson, J.N. 2833:What the Tortoise Said to Achilles 1452:To paraphrase: if one could write 1392:. Dividing both sides by 2 yields 902:is odd, for all positive integers 480:, respectively, for some integers 25: 6036: 3752: 3197:Quine, Willard Van Orman (1961). 2704: 828:must also be odd, because adding 5957: 5531: 3758: 2866:. University of British Columbia 2770: 2756: 2455: 2443: 2427: 706:is true for all natural numbers 412:Proofs may be admired for their 377:not provable within the system. 3564: 3510: 3474: 3452: 3406: 3395: 3380: 3369: 3356: 3343: 3312: 3281: 3268: 3249: 3238: 3229: 3220: 3190: 3154: 3110: 3075: 2938:Discrete Mathematics with Proof 2568:mathematical methods of physics 2405: 2048:{\displaystyle a=b={\sqrt {2}}} 540:Proof by mathematical induction 434: 144:quasi-empiricism in mathematics 3716:, Cambridge University Press, 3610:, Princeton University Press, 3481:Lesmoir-Gordon, Nigel (2000). 3049: 3027:; Kneale, Martha (May 1985) . 3017: 2970: 2961: 2929: 2878: 2852: 2088:is irrational so we can write 1755: 1715: 1649: 1609: 1348:. Squaring both sides yields 2 1341:{\displaystyle b{\sqrt {2}}=a} 1101:{\displaystyle x^{2}=x\cdot x} 399:analytic–synthetic distinction 280:. In the 10th century CE, the 227:(300 BCE), who introduced the 13: 1: 5492:History of mathematical logic 3351:American Mathematical Monthly 2845: 2571:applied to analyze data in a 2150:{\displaystyle b={\sqrt {2}}} 842: + 1 = 2( 826: − 1) + 2 261:, including a proof that the 5417:Primitive recursive function 3680:; Simons, Rogers A. (2008). 3517:Herbst, Patricio G. (2002). 3485:Introducing Fractal Geometry 2715:Sometimes, the abbreviation 2636:or information is acquired. 2613:, and may be less than full 2534:Statistical proof using data 2300:Statistical proof using data 1360:is even, which implies that 278:medieval Islamic mathematics 92:arguments or non-exhaustive 7: 2936:Gossett, Eric (July 2009). 2807:List of mathematical proofs 2749: 2418:in the case of the (3,4,5) 2288:probabilistic number theory 1938:{\displaystyle {\sqrt {2}}} 1469:{\displaystyle {\sqrt {2}}} 1441:{\displaystyle {\sqrt {2}}} 1311:are non-zero integers with 1259:{\displaystyle {\sqrt {2}}} 1227:{\displaystyle {\sqrt {2}}} 456:Consider two even integers 309:, who used it to prove the 10: 6041: 4481:Schröder–Bernstein theorem 4208:Monadic predicate calculus 3867:Foundations of mathematics 3432:Cambridge University Press 3261:February 18, 2012, at the 3199:"Two Dogmas of Empiricism" 2986:Cambridge University Press 2708: 2643: 2594: 2537: 2478: 2366: 2309: 2267: 1867: 1841: 1796: 1536: 1517: 1487: 1408:must be even. However, if 1193: 919: 543: 438: 165: 136:formal and informal proofs 134:. The distinction between 5952: 5912: 5884: 5877: 5829:Necessity and sufficiency 5732: 5697: 5649: 5603: 5585: 5577: 5527: 5514:Philosophy of mathematics 5463:Automated theorem proving 5445: 5340: 5172: 5065: 4917: 4634: 4610: 4588:Von Neumann–Bernays–Gödel 4533: 4427: 4331: 4229: 4220: 4147: 4082: 3988: 3910: 3827: 3731:Hammack, Richard (2018), 3390:proof"" (Derogatory use.) 2797:List of incomplete proofs 2787:Automated theorem proving 2721:"quod erat demonstrandum" 2630:assessment of likelihoods 2377:did not use proofs, from 568:proof by infinite descent 198:ancient Greek mathematics 156:mathematics as a language 152:philosophy of mathematics 6010:Mathematical terminology 3170:Handbook of Proof Theory 3029:The development of logic 2735:" or "halmos" after its 2640:Proofs as mental objects 2391:experimental mathematics 2383:foundational mathematics 2369:Experimental mathematics 2306:Computer-assisted proofs 1858:double counting argument 1448:is an irrational number. 1366:#Proof by contraposition 945:contrapositive statement 407:Two Dogmas of Empiricism 5164:Self-verifying theories 4985:Tarski's axiomatization 3936:Tarski's undefinability 3931:incompleteness theorems 3617:2027/mdp.39015008206248 3540:10.1023/A:1020264906740 3033:Oxford University Press 2744:(220E(hex) = 8718(dec)) 2632:of hypotheses when new 2624:Bayesian analysis uses 2312:Computer-assisted proof 2296:mathematical statistics 1921:. This proof uses that 1828:probabilistic algorithm 927:Proof by contraposition 916:Proof by contraposition 5538:Mathematics portal 5149:Proof of impossibility 4797:propositional variable 4107:Propositional calculus 3577:onemathematicalcat.org 3466:on February 15, 2009. 2619:mathematical induction 2510: 2326:Undecidable statements 2292:analytic number theory 2254: 2253:{\displaystyle a^{b}.} 2224: 2151: 2121: 2082: 2049: 2013: 1976: 1939: 1911: 1772: 1732: 1686: 1685:{\displaystyle \dots } 1666: 1626: 1586: 1539:Closed chain inference 1533:Closed chain inference 1500:transcendental numbers 1470: 1442: 1342: 1297: 1260: 1228: 1196:Proof by contradiction 1190:Proof by contradiction 1179: 1156: 1135:is not even. Thus, if 1129: 1102: 1063: 1043: 1019: 999: 972: 940:" by establishing the 546:Mathematical induction 375:undecidable statements 334:Non-Euclidean geometry 301:was introduced in the 66:mathematical statement 50: 5964:Philosophy portal 5407:Kolmogorov complexity 5360:Computably enumerable 5260:Model complete theory 5052:Principia Mathematica 4112:Propositional formula 3941:Banach–Tarski paradox 3712:Velleman, D. (2006), 3364:Journal of Philosophy 2942:John Wiley & Sons 2817:Proof by intimidation 2812:Nonconstructive proof 2628:to update a person's 2515:mathematical exercise 2508: 2469:missing square puzzle 2255: 2225: 2152: 2122: 2083: 2050: 2014: 1977: 1940: 1912: 1910:{\displaystyle a^{b}} 1870:Nonconstructive proof 1864:Nonconstructive proof 1773: 1733: 1687: 1667: 1627: 1587: 1490:Proof by construction 1484:Proof by construction 1471: 1443: 1343: 1298: 1261: 1229: 1208:logical contradiction 1180: 1157: 1155:{\displaystyle x^{2}} 1130: 1128:{\displaystyle x^{2}} 1103: 1064: 1044: 1020: 1000: 998:{\displaystyle x^{2}} 973: 680:is true implies that 534:distributive property 397:, who introduced the 243:. Euclid's book, the 184:(to try), and German 162:History and etymology 140:mathematical practice 35: 6025:Sources of knowledge 5355:Church–Turing thesis 5342:Computability theory 4551:continuum hypothesis 4069:Square of opposition 3927:Gödel's completeness 3767:at Wikimedia Commons 3656:; Daoud, A. (2011), 3635:Fallis, Don (2002), 3183:. See in particular 2905:Cupillari, Antonella 2839:Zero-knowledge proof 2822:Termination analysis 2528:mathematical objects 2495:prime number theorem 2387:mathematical objects 2278:, such as involving 2234: 2161: 2131: 2092: 2059: 2023: 1990: 1953: 1925: 1894: 1799:Probabilistic method 1787:material conditional 1742: 1696: 1676: 1636: 1596: 1550: 1456: 1428: 1319: 1270: 1246: 1214: 1203:reductio ad absurdum 1169: 1139: 1112: 1073: 1053: 1033: 1009: 982: 962: 942:logically equivalent 423:Proofs from THE BOOK 416:. The mathematician 405:argued in his 1951 " 330:Axiomatic set theory 299:arithmetic sequences 206:Hippocrates of Chios 6015:Mathematical proofs 5626:Philosophy of logic 5509:Mathematical object 5400:P versus NP problem 5365:Computable function 5159:Reverse mathematics 5085:Logical consequence 4962:primitive recursive 4957:elementary function 4730:Free/bound variable 4583:Tarski–Grothendieck 4102:Logical connectives 4032:Logical equivalence 3882:Logical consequence 3779:about proofs, in a 3737:, Richard Hammack, 3133:1987NYASA.500..253M 3062:Archive ouverte HAL 2802:List of long proofs 2668:language of thought 2650:Language of thought 2577:observational study 2416:Pythagorean theorem 2412:proof without words 1876:mathematical object 1844:Combinatorial proof 1838:Combinatorial proof 1793:Probabilistic proof 1520:Proof by exhaustion 1514:Proof by exhaustion 1502:by constructing an 1368:). So we can write 556:inductive reasoning 414:mathematical beauty 251:Pythagorean theorem 126:, written fully in 94:inductive reasoning 86:deductive reasoning 6005:Mathematical logic 5925:Rules of inference 5894:Mathematical logic 5636:Semantics of logic 5307:Transfer principle 5270:Semantics of logic 5255:Categorical theory 5231:Non-standard model 4745:Logical connective 3872:Information theory 3821:Mathematical logic 3765:Mathematical proof 3689:Solow, D. (2004), 3641:Logique et Analyse 3571:Dr. Fisher Burns. 3256:Proof by induction 2911:(Third ed.). 2827:Thought experiment 2778:Mathematics portal 2581:physical cosmology 2511: 2340:Euclidean geometry 2336:parallel postulate 2319:four color theorem 2250: 2220: 2157:. This then gives 2147: 2117: 2078: 2045: 2009: 1972: 1935: 1907: 1881:irrational numbers 1824:Mertens conjecture 1820:Collatz conjecture 1809:existence theorems 1805:probability theory 1768: 1728: 1682: 1662: 1622: 1582: 1527:four color theorem 1466: 1438: 1338: 1293: 1256: 1224: 1175: 1152: 1125: 1098: 1059: 1049:is not even. Then 1039: 1015: 995: 968: 932:the statement "if 586:= {1, 2, 3, 4, ... 488:. Then the sum is 354:mathematical logic 340:Nature and purpose 313:and properties of 291:irrational numbers 263:square root of two 212:(408–355 BCE) and 204:(624–546 BCE) and 55:mathematical proof 51: 5992: 5991: 5948: 5947: 5782:Deductive closure 5728: 5727: 5667:Critical thinking 5545: 5544: 5477:Abstract category 5280:Theories of truth 5090:Rule of inference 5080:Natural deduction 5061: 5060: 4606: 4605: 4311:Cartesian product 4216: 4215: 4122:Many-valued logic 4097:Boolean functions 3980:Russell's paradox 3955:diagonal argument 3852:First-order logic 3763:Media related to 3744:978-0-9894721-3-5 3723:978-0-521-67599-4 3704:978-0-471-68058-1 3669:978-0-646-54509-7 3500:978-1-84046-123-7 3441:978-0-521-35253-6 3414:Mumford, David B. 3336:978-3-662-49870-5 3305:978-3-662-58352-4 3235:Cupillari, p. 46. 3226:Cupillari, p. 20. 3179:978-0-08-053318-6 3085:(January 1990) . 3042:978-0-19-824773-9 2995:978-0-521-31803-7 2922:978-0-12-088509-1 2764:Philosophy portal 2745: 2672:empirical science 2601:Bayesian analysis 2550:Bayesian analysis 2540:Statistical proof 2438:500–200 BCE. 2375:Eudoxus of Cnidus 2302:" section below. 2298:. See also the " 2270:Statistical proof 2206: 2194: 2182: 2175: 2145: 2114: 2107: 2075: 2068: 2043: 2006: 1999: 1969: 1962: 1933: 1832:testing primality 1464: 1436: 1330: 1291: 1278: 1254: 1236:irrational number 1222: 1178:{\displaystyle x} 1062:{\displaystyle x} 1042:{\displaystyle x} 1018:{\displaystyle x} 971:{\displaystyle x} 854:+1) − 1 846:+1) − 1 658:is true whenever 315:Pascal's triangle 128:symbolic language 16:(Redirected from 6032: 5962: 5961: 5960: 5882: 5881: 5647: 5646: 5611:Computer science 5572: 5565: 5558: 5549: 5548: 5536: 5535: 5487:History of logic 5482:Category of sets 5375:Decision problem 5154:Ordinal analysis 5095:Sequent calculus 4993:Boolean algebras 4933: 4932: 4907: 4878:logical/constant 4632: 4631: 4618: 4541:Zermelo–Fraenkel 4292:Set operations: 4227: 4226: 4164: 3995: 3994: 3975:Löwenheim–Skolem 3862:Formal semantics 3814: 3807: 3800: 3791: 3790: 3762: 3747: 3726: 3707: 3685: 3672: 3648: 3630: 3619: 3588: 3587: 3585: 3583: 3568: 3562: 3561: 3551: 3523: 3514: 3508: 3507: 3488: 3478: 3472: 3471: 3462:. Archived from 3456: 3450: 3449: 3418:Series, Caroline 3410: 3404: 3399: 3393: 3384: 3378: 3373: 3367: 3360: 3354: 3347: 3341: 3340: 3316: 3310: 3309: 3285: 3279: 3272: 3266: 3253: 3247: 3242: 3236: 3233: 3227: 3224: 3218: 3217: 3215: 3213: 3203: 3194: 3188: 3182: 3158: 3152: 3151: 3114: 3108: 3107: 3089:(6th ed.). 3079: 3073: 3072: 3070: 3068: 3053: 3047: 3046: 3031:(New ed.). 3021: 3015: 3009: 3000: 2999: 2974: 2968: 2965: 2959: 2958: 2933: 2927: 2926: 2901: 2895: 2894: 2882: 2876: 2875: 2873: 2871: 2856: 2780: 2775: 2774: 2766: 2761: 2760: 2759: 2743: 2573:particle physics 2501:Two-column proof 2491:complex analysis 2481:Elementary proof 2475:Elementary proof 2459: 2447: 2431: 2401:Related concepts 2395:fractal geometry 2276:pure mathematics 2259: 2257: 2256: 2251: 2246: 2245: 2229: 2227: 2226: 2221: 2213: 2212: 2207: 2202: 2196: 2195: 2190: 2188: 2184: 2183: 2178: 2176: 2171: 2156: 2154: 2153: 2148: 2146: 2141: 2126: 2124: 2123: 2118: 2116: 2115: 2110: 2108: 2103: 2087: 2085: 2084: 2079: 2077: 2076: 2071: 2069: 2064: 2054: 2052: 2051: 2046: 2044: 2039: 2018: 2016: 2015: 2010: 2008: 2007: 2002: 2000: 1995: 1981: 1979: 1978: 1973: 1971: 1970: 1965: 1963: 1958: 1949:), but not that 1944: 1942: 1941: 1936: 1934: 1929: 1916: 1914: 1913: 1908: 1906: 1905: 1777: 1775: 1774: 1769: 1767: 1766: 1754: 1753: 1737: 1735: 1734: 1729: 1727: 1726: 1714: 1713: 1691: 1689: 1688: 1683: 1671: 1669: 1668: 1663: 1661: 1660: 1648: 1647: 1631: 1629: 1628: 1623: 1621: 1620: 1608: 1607: 1591: 1589: 1588: 1583: 1581: 1580: 1562: 1561: 1504:explicit example 1496:Joseph Liouville 1475: 1473: 1472: 1467: 1465: 1460: 1447: 1445: 1444: 1439: 1437: 1432: 1347: 1345: 1344: 1339: 1331: 1326: 1313:no common factor 1302: 1300: 1299: 1294: 1292: 1284: 1279: 1274: 1265: 1263: 1262: 1257: 1255: 1250: 1233: 1231: 1230: 1225: 1223: 1218: 1184: 1182: 1181: 1176: 1161: 1159: 1158: 1153: 1151: 1150: 1134: 1132: 1131: 1126: 1124: 1123: 1107: 1105: 1104: 1099: 1085: 1084: 1068: 1066: 1065: 1060: 1048: 1046: 1045: 1040: 1024: 1022: 1021: 1016: 1004: 1002: 1001: 996: 994: 993: 977: 975: 974: 969: 907: 901: 888: 877: 866: 855: 847: 831: 827: 819: 808: 800: 788: 781: 778:when divided by 777: 773: 769: 761: 747: 739: 724: 711: 705: 690: 679: 668: 657: 641: 634: 623: 610: 604: 598: 587: 554:, not a form of 452:is always even: 430:Methods of proof 383:proof assistants 360:is written in a 311:binomial theorem 229:axiomatic method 168:History of logic 148:folk mathematics 146:, and so-called 113:natural language 21: 6040: 6039: 6035: 6034: 6033: 6031: 6030: 6029: 5995: 5994: 5993: 5988: 5958: 5956: 5944: 5908: 5899:Boolean algebra 5873: 5724: 5715:Metamathematics 5693: 5645: 5599: 5581: 5576: 5546: 5541: 5530: 5523: 5468:Category theory 5458:Algebraic logic 5441: 5412:Lambda calculus 5350:Church encoding 5336: 5312:Truth predicate 5168: 5134:Complete theory 5057: 4926: 4922: 4918: 4913: 4905: 4625: and  4621: 4616: 4602: 4578:New Foundations 4546:axiom of choice 4529: 4491:Gödel numbering 4431: and  4423: 4327: 4212: 4162: 4143: 4092:Boolean algebra 4078: 4042:Equiconsistency 4007:Classical logic 3984: 3965:Halting problem 3953: and  3929: and  3917: and  3916: 3911:Theorems ( 3906: 3823: 3818: 3755: 3745: 3724: 3705: 3670: 3628: 3597: 3595:Further reading 3592: 3591: 3581: 3579: 3569: 3565: 3521: 3515: 3511: 3501: 3479: 3475: 3458: 3457: 3453: 3442: 3411: 3407: 3400: 3396: 3385: 3381: 3374: 3370: 3361: 3357: 3348: 3344: 3337: 3317: 3313: 3306: 3286: 3282: 3273: 3269: 3263:Wayback Machine 3254: 3250: 3243: 3239: 3234: 3230: 3225: 3221: 3211: 3209: 3201: 3195: 3191: 3180: 3166:Buss, Samuel R. 3162:Buss, Samuel R. 3159: 3155: 3115: 3111: 3101: 3093:. p. 141. 3083:Eves, Howard W. 3080: 3076: 3066: 3064: 3054: 3050: 3043: 3025:Kneale, William 3022: 3018: 3010: 3003: 2996: 2975: 2971: 2966: 2962: 2952: 2934: 2930: 2923: 2902: 2898: 2883: 2879: 2869: 2867: 2857: 2853: 2848: 2843: 2776: 2769: 2762: 2757: 2755: 2752: 2713: 2707: 2680: 2652: 2644:Main articles: 2642: 2607:inductive logic 2603: 2597:Inductive logic 2595:Main articles: 2593: 2556:of data. While 2542: 2536: 2524: 2503: 2483: 2477: 2463: 2460: 2451: 2448: 2439: 2436:Zhoubi Suanjing 2432: 2408: 2403: 2371: 2365: 2328: 2314: 2308: 2272: 2266: 2241: 2237: 2235: 2232: 2231: 2208: 2201: 2200: 2189: 2177: 2170: 2169: 2165: 2164: 2162: 2159: 2158: 2140: 2132: 2129: 2128: 2109: 2102: 2101: 2093: 2090: 2089: 2070: 2063: 2062: 2060: 2057: 2056: 2038: 2024: 2021: 2020: 2001: 1994: 1993: 1991: 1988: 1987: 1964: 1957: 1956: 1954: 1951: 1950: 1928: 1926: 1923: 1922: 1919:rational number 1901: 1897: 1895: 1892: 1891: 1872: 1866: 1846: 1840: 1801: 1795: 1762: 1758: 1749: 1745: 1743: 1740: 1739: 1722: 1718: 1703: 1699: 1697: 1694: 1693: 1677: 1674: 1673: 1656: 1652: 1643: 1639: 1637: 1634: 1633: 1616: 1612: 1603: 1599: 1597: 1594: 1593: 1576: 1572: 1557: 1553: 1551: 1548: 1547: 1541: 1535: 1522: 1516: 1492: 1486: 1459: 1457: 1454: 1453: 1431: 1429: 1426: 1425: 1325: 1320: 1317: 1316: 1283: 1273: 1271: 1268: 1267: 1249: 1247: 1244: 1243: 1217: 1215: 1212: 1211: 1198: 1192: 1185:has to be even. 1170: 1167: 1166: 1146: 1142: 1140: 1137: 1136: 1119: 1115: 1113: 1110: 1109: 1080: 1076: 1074: 1071: 1070: 1054: 1051: 1050: 1034: 1031: 1030: 1010: 1007: 1006: 989: 985: 983: 980: 979: 963: 960: 959: 924: 918: 903: 895: 879: 868: 857: 849: 833: 829: 821: 810: 802: 796: 783: 779: 775: 771: 763: 756: 741: 730: 718: 707: 696: 681: 670: 669:is true, i.e., 659: 648: 636: 625: 624:is true, i.e., 618: 606: 600: 589: 582: 579:natural numbers 548: 542: 443: 437: 432: 362:formal language 342: 326:data structures 295:inductive proof 241:deductive logic 233:undefined terms 170: 164: 28: 23: 22: 18:Theorem-proving 15: 12: 11: 5: 6038: 6028: 6027: 6022: 6017: 6012: 6007: 5990: 5989: 5987: 5986: 5981: 5971: 5966: 5953: 5950: 5949: 5946: 5945: 5943: 5942: 5937: 5932: 5927: 5922: 5916: 5914: 5910: 5909: 5907: 5906: 5901: 5896: 5890: 5888: 5879: 5875: 5874: 5872: 5871: 5866: 5861: 5856: 5851: 5846: 5841: 5836: 5831: 5826: 5821: 5816: 5811: 5806: 5805: 5804: 5794: 5789: 5784: 5779: 5774: 5773: 5772: 5767: 5757: 5752: 5747: 5742: 5736: 5734: 5730: 5729: 5726: 5725: 5723: 5722: 5717: 5712: 5707: 5701: 5699: 5695: 5694: 5692: 5691: 5686: 5681: 5676: 5675: 5674: 5669: 5659: 5653: 5651: 5644: 5643: 5638: 5633: 5628: 5623: 5618: 5613: 5607: 5605: 5601: 5600: 5598: 5597: 5592: 5586: 5583: 5582: 5575: 5574: 5567: 5560: 5552: 5543: 5542: 5528: 5525: 5524: 5522: 5521: 5516: 5511: 5506: 5501: 5500: 5499: 5489: 5484: 5479: 5470: 5465: 5460: 5455: 5453:Abstract logic 5449: 5447: 5443: 5442: 5440: 5439: 5434: 5432:Turing machine 5429: 5424: 5419: 5414: 5409: 5404: 5403: 5402: 5397: 5392: 5387: 5382: 5372: 5370:Computable set 5367: 5362: 5357: 5352: 5346: 5344: 5338: 5337: 5335: 5334: 5329: 5324: 5319: 5314: 5309: 5304: 5299: 5298: 5297: 5292: 5287: 5277: 5272: 5267: 5265:Satisfiability 5262: 5257: 5252: 5251: 5250: 5240: 5239: 5238: 5228: 5227: 5226: 5221: 5216: 5211: 5206: 5196: 5195: 5194: 5189: 5182:Interpretation 5178: 5176: 5170: 5169: 5167: 5166: 5161: 5156: 5151: 5146: 5136: 5131: 5130: 5129: 5128: 5127: 5117: 5112: 5102: 5097: 5092: 5087: 5082: 5077: 5071: 5069: 5063: 5062: 5059: 5058: 5056: 5055: 5047: 5046: 5045: 5044: 5039: 5038: 5037: 5032: 5027: 5007: 5006: 5005: 5003:minimal axioms 5000: 4989: 4988: 4987: 4976: 4975: 4974: 4969: 4964: 4959: 4954: 4949: 4936: 4934: 4915: 4914: 4912: 4911: 4910: 4909: 4897: 4892: 4891: 4890: 4885: 4880: 4875: 4865: 4860: 4855: 4850: 4849: 4848: 4843: 4833: 4832: 4831: 4826: 4821: 4816: 4806: 4801: 4800: 4799: 4794: 4789: 4779: 4778: 4777: 4772: 4767: 4762: 4757: 4752: 4742: 4737: 4732: 4727: 4726: 4725: 4720: 4715: 4710: 4700: 4695: 4693:Formation rule 4690: 4685: 4684: 4683: 4678: 4668: 4667: 4666: 4656: 4651: 4646: 4641: 4635: 4629: 4612:Formal systems 4608: 4607: 4604: 4603: 4601: 4600: 4595: 4590: 4585: 4580: 4575: 4570: 4565: 4560: 4555: 4554: 4553: 4548: 4537: 4535: 4531: 4530: 4528: 4527: 4526: 4525: 4515: 4510: 4509: 4508: 4501:Large cardinal 4498: 4493: 4488: 4483: 4478: 4464: 4463: 4462: 4457: 4452: 4437: 4435: 4425: 4424: 4422: 4421: 4420: 4419: 4414: 4409: 4399: 4394: 4389: 4384: 4379: 4374: 4369: 4364: 4359: 4354: 4349: 4344: 4338: 4336: 4329: 4328: 4326: 4325: 4324: 4323: 4318: 4313: 4308: 4303: 4298: 4290: 4289: 4288: 4283: 4273: 4268: 4266:Extensionality 4263: 4261:Ordinal number 4258: 4248: 4243: 4242: 4241: 4230: 4224: 4218: 4217: 4214: 4213: 4211: 4210: 4205: 4200: 4195: 4190: 4185: 4180: 4179: 4178: 4168: 4167: 4166: 4153: 4151: 4145: 4144: 4142: 4141: 4140: 4139: 4134: 4129: 4119: 4114: 4109: 4104: 4099: 4094: 4088: 4086: 4080: 4079: 4077: 4076: 4071: 4066: 4061: 4056: 4051: 4046: 4045: 4044: 4034: 4029: 4024: 4019: 4014: 4009: 4003: 4001: 3992: 3986: 3985: 3983: 3982: 3977: 3972: 3967: 3962: 3957: 3945:Cantor's  3943: 3938: 3933: 3923: 3921: 3908: 3907: 3905: 3904: 3899: 3894: 3889: 3884: 3879: 3874: 3869: 3864: 3859: 3854: 3849: 3844: 3843: 3842: 3831: 3829: 3825: 3824: 3817: 3816: 3809: 3802: 3794: 3788: 3787: 3773: 3768: 3754: 3753:External links 3751: 3750: 3749: 3743: 3728: 3722: 3709: 3703: 3686: 3674: 3668: 3650: 3632: 3626: 3596: 3593: 3590: 3589: 3563: 3534:(3): 283–312. 3509: 3499: 3473: 3451: 3440: 3405: 3394: 3379: 3368: 3355: 3342: 3335: 3311: 3304: 3280: 3267: 3248: 3237: 3228: 3219: 3189: 3178: 3153: 3127:(1): 253–77 , 3109: 3100:978-0030295584 3099: 3074: 3048: 3041: 3016: 3001: 2994: 2969: 2960: 2951:978-0470457931 2950: 2944:. p. 86. 2928: 2921: 2913:Academic Press 2896: 2877: 2860:Bill Casselman 2850: 2849: 2847: 2844: 2842: 2841: 2836: 2829: 2824: 2819: 2814: 2809: 2804: 2799: 2794: 2789: 2783: 2782: 2781: 2767: 2751: 2748: 2709:Main article: 2706: 2705:Ending a proof 2703: 2679: 2676: 2641: 2638: 2626:Bayes' theorem 2592: 2589: 2575:experiment or 2538:Main article: 2535: 2532: 2523: 2520: 2502: 2499: 2479:Main article: 2476: 2473: 2465: 2464: 2461: 2454: 2452: 2449: 2442: 2440: 2433: 2426: 2407: 2404: 2402: 2399: 2367:Main article: 2364: 2361: 2327: 2324: 2310:Main article: 2307: 2304: 2284:chaotic series 2268:Main article: 2265: 2262: 2261: 2260: 2249: 2244: 2240: 2219: 2216: 2211: 2205: 2199: 2193: 2187: 2181: 2174: 2168: 2144: 2139: 2136: 2113: 2106: 2100: 2097: 2074: 2067: 2042: 2037: 2034: 2031: 2028: 2005: 1998: 1968: 1961: 1932: 1904: 1900: 1868:Main article: 1865: 1862: 1842:Main article: 1839: 1836: 1797:Main article: 1794: 1791: 1765: 1761: 1757: 1752: 1748: 1725: 1721: 1717: 1712: 1709: 1706: 1702: 1681: 1659: 1655: 1651: 1646: 1642: 1619: 1615: 1611: 1606: 1602: 1579: 1575: 1571: 1568: 1565: 1560: 1556: 1537:Main article: 1534: 1531: 1518:Main article: 1515: 1512: 1508:counterexample 1488:Main article: 1485: 1482: 1463: 1450: 1449: 1435: 1337: 1334: 1329: 1324: 1290: 1287: 1282: 1277: 1253: 1221: 1194:Main article: 1191: 1188: 1187: 1186: 1174: 1149: 1145: 1122: 1118: 1097: 1094: 1091: 1088: 1083: 1079: 1058: 1038: 1014: 1005:is even, then 992: 988: 967: 922:Contraposition 920:Main article: 917: 914: 910: 909: 900: − 1 890: 807: − 1 790: 746: − 1 723: − 1 715: 714: 692: 643: 544:Main article: 541: 538: 526: 525: 500: + 2 476: = 2 468: = 2 439:Main article: 436: 433: 431: 428: 341: 338: 284:mathematician 163: 160: 120:informal logic 107:Proofs employ 26: 9: 6: 4: 3: 2: 6037: 6026: 6023: 6021: 6018: 6016: 6013: 6011: 6008: 6006: 6003: 6002: 6000: 5985: 5982: 5979: 5975: 5972: 5970: 5967: 5965: 5955: 5954: 5951: 5941: 5940:Logic symbols 5938: 5936: 5933: 5931: 5928: 5926: 5923: 5921: 5918: 5917: 5915: 5911: 5905: 5902: 5900: 5897: 5895: 5892: 5891: 5889: 5887: 5883: 5880: 5876: 5870: 5867: 5865: 5862: 5860: 5857: 5855: 5852: 5850: 5847: 5845: 5842: 5840: 5837: 5835: 5832: 5830: 5827: 5825: 5822: 5820: 5819:Logical truth 5817: 5815: 5812: 5810: 5807: 5803: 5800: 5799: 5798: 5795: 5793: 5790: 5788: 5785: 5783: 5780: 5778: 5775: 5771: 5768: 5766: 5763: 5762: 5761: 5760:Contradiction 5758: 5756: 5753: 5751: 5748: 5746: 5743: 5741: 5738: 5737: 5735: 5731: 5721: 5718: 5716: 5713: 5711: 5708: 5706: 5705:Argumentation 5703: 5702: 5700: 5696: 5690: 5689:Philosophical 5687: 5685: 5684:Non-classical 5682: 5680: 5677: 5673: 5670: 5668: 5665: 5664: 5663: 5660: 5658: 5655: 5654: 5652: 5648: 5642: 5639: 5637: 5634: 5632: 5629: 5627: 5624: 5622: 5619: 5617: 5614: 5612: 5609: 5608: 5606: 5602: 5596: 5593: 5591: 5588: 5587: 5584: 5580: 5573: 5568: 5566: 5561: 5559: 5554: 5553: 5550: 5540: 5539: 5534: 5526: 5520: 5517: 5515: 5512: 5510: 5507: 5505: 5502: 5498: 5495: 5494: 5493: 5490: 5488: 5485: 5483: 5480: 5478: 5474: 5471: 5469: 5466: 5464: 5461: 5459: 5456: 5454: 5451: 5450: 5448: 5444: 5438: 5435: 5433: 5430: 5428: 5427:Recursive set 5425: 5423: 5420: 5418: 5415: 5413: 5410: 5408: 5405: 5401: 5398: 5396: 5393: 5391: 5388: 5386: 5383: 5381: 5378: 5377: 5376: 5373: 5371: 5368: 5366: 5363: 5361: 5358: 5356: 5353: 5351: 5348: 5347: 5345: 5343: 5339: 5333: 5330: 5328: 5325: 5323: 5320: 5318: 5315: 5313: 5310: 5308: 5305: 5303: 5300: 5296: 5293: 5291: 5288: 5286: 5283: 5282: 5281: 5278: 5276: 5273: 5271: 5268: 5266: 5263: 5261: 5258: 5256: 5253: 5249: 5246: 5245: 5244: 5241: 5237: 5236:of arithmetic 5234: 5233: 5232: 5229: 5225: 5222: 5220: 5217: 5215: 5212: 5210: 5207: 5205: 5202: 5201: 5200: 5197: 5193: 5190: 5188: 5185: 5184: 5183: 5180: 5179: 5177: 5175: 5171: 5165: 5162: 5160: 5157: 5155: 5152: 5150: 5147: 5144: 5143:from ZFC 5140: 5137: 5135: 5132: 5126: 5123: 5122: 5121: 5118: 5116: 5113: 5111: 5108: 5107: 5106: 5103: 5101: 5098: 5096: 5093: 5091: 5088: 5086: 5083: 5081: 5078: 5076: 5073: 5072: 5070: 5068: 5064: 5054: 5053: 5049: 5048: 5043: 5042:non-Euclidean 5040: 5036: 5033: 5031: 5028: 5026: 5025: 5021: 5020: 5018: 5015: 5014: 5012: 5008: 5004: 5001: 4999: 4996: 4995: 4994: 4990: 4986: 4983: 4982: 4981: 4977: 4973: 4970: 4968: 4965: 4963: 4960: 4958: 4955: 4953: 4950: 4948: 4945: 4944: 4942: 4938: 4937: 4935: 4930: 4924: 4919:Example  4916: 4908: 4903: 4902: 4901: 4898: 4896: 4893: 4889: 4886: 4884: 4881: 4879: 4876: 4874: 4871: 4870: 4869: 4866: 4864: 4861: 4859: 4856: 4854: 4851: 4847: 4844: 4842: 4839: 4838: 4837: 4834: 4830: 4827: 4825: 4822: 4820: 4817: 4815: 4812: 4811: 4810: 4807: 4805: 4802: 4798: 4795: 4793: 4790: 4788: 4785: 4784: 4783: 4780: 4776: 4773: 4771: 4768: 4766: 4763: 4761: 4758: 4756: 4753: 4751: 4748: 4747: 4746: 4743: 4741: 4738: 4736: 4733: 4731: 4728: 4724: 4721: 4719: 4716: 4714: 4711: 4709: 4706: 4705: 4704: 4701: 4699: 4696: 4694: 4691: 4689: 4686: 4682: 4679: 4677: 4676:by definition 4674: 4673: 4672: 4669: 4665: 4662: 4661: 4660: 4657: 4655: 4652: 4650: 4647: 4645: 4642: 4640: 4637: 4636: 4633: 4630: 4628: 4624: 4619: 4613: 4609: 4599: 4596: 4594: 4591: 4589: 4586: 4584: 4581: 4579: 4576: 4574: 4571: 4569: 4566: 4564: 4563:Kripke–Platek 4561: 4559: 4556: 4552: 4549: 4547: 4544: 4543: 4542: 4539: 4538: 4536: 4532: 4524: 4521: 4520: 4519: 4516: 4514: 4511: 4507: 4504: 4503: 4502: 4499: 4497: 4494: 4492: 4489: 4487: 4484: 4482: 4479: 4476: 4472: 4468: 4465: 4461: 4458: 4456: 4453: 4451: 4448: 4447: 4446: 4442: 4439: 4438: 4436: 4434: 4430: 4426: 4418: 4415: 4413: 4410: 4408: 4407:constructible 4405: 4404: 4403: 4400: 4398: 4395: 4393: 4390: 4388: 4385: 4383: 4380: 4378: 4375: 4373: 4370: 4368: 4365: 4363: 4360: 4358: 4355: 4353: 4350: 4348: 4345: 4343: 4340: 4339: 4337: 4335: 4330: 4322: 4319: 4317: 4314: 4312: 4309: 4307: 4304: 4302: 4299: 4297: 4294: 4293: 4291: 4287: 4284: 4282: 4279: 4278: 4277: 4274: 4272: 4269: 4267: 4264: 4262: 4259: 4257: 4253: 4249: 4247: 4244: 4240: 4237: 4236: 4235: 4232: 4231: 4228: 4225: 4223: 4219: 4209: 4206: 4204: 4201: 4199: 4196: 4194: 4191: 4189: 4186: 4184: 4181: 4177: 4174: 4173: 4172: 4169: 4165: 4160: 4159: 4158: 4155: 4154: 4152: 4150: 4146: 4138: 4135: 4133: 4130: 4128: 4125: 4124: 4123: 4120: 4118: 4115: 4113: 4110: 4108: 4105: 4103: 4100: 4098: 4095: 4093: 4090: 4089: 4087: 4085: 4084:Propositional 4081: 4075: 4072: 4070: 4067: 4065: 4062: 4060: 4057: 4055: 4052: 4050: 4047: 4043: 4040: 4039: 4038: 4035: 4033: 4030: 4028: 4025: 4023: 4020: 4018: 4015: 4013: 4012:Logical truth 4010: 4008: 4005: 4004: 4002: 4000: 3996: 3993: 3991: 3987: 3981: 3978: 3976: 3973: 3971: 3968: 3966: 3963: 3961: 3958: 3956: 3952: 3948: 3944: 3942: 3939: 3937: 3934: 3932: 3928: 3925: 3924: 3922: 3920: 3914: 3909: 3903: 3900: 3898: 3895: 3893: 3890: 3888: 3885: 3883: 3880: 3878: 3875: 3873: 3870: 3868: 3865: 3863: 3860: 3858: 3855: 3853: 3850: 3848: 3845: 3841: 3838: 3837: 3836: 3833: 3832: 3830: 3826: 3822: 3815: 3810: 3808: 3803: 3801: 3796: 3795: 3792: 3786: 3782: 3778: 3774: 3772: 3769: 3766: 3761: 3757: 3756: 3746: 3740: 3736: 3735: 3734:Book of Proof 3729: 3725: 3719: 3715: 3710: 3706: 3700: 3696: 3692: 3687: 3683: 3679: 3675: 3671: 3665: 3662:, Kew Books, 3661: 3660: 3655: 3651: 3646: 3642: 3638: 3633: 3629: 3627:9780691080055 3623: 3618: 3613: 3609: 3608: 3603: 3599: 3598: 3578: 3574: 3567: 3559: 3555: 3550: 3549:2027.42/42653 3545: 3541: 3537: 3533: 3529: 3528: 3520: 3513: 3506: 3502: 3496: 3492: 3487: 3486: 3477: 3470: 3465: 3461: 3455: 3448: 3443: 3437: 3433: 3429: 3428: 3423: 3422:Wright, David 3419: 3415: 3409: 3403: 3398: 3392: 3389: 3383: 3377: 3372: 3365: 3359: 3352: 3346: 3338: 3332: 3328: 3324: 3323: 3315: 3307: 3301: 3297: 3293: 3292: 3284: 3277: 3271: 3264: 3260: 3257: 3252: 3246: 3241: 3232: 3223: 3207: 3200: 3193: 3186: 3181: 3175: 3171: 3167: 3163: 3157: 3150: 3146: 3142: 3138: 3134: 3130: 3126: 3122: 3121: 3113: 3106: 3102: 3096: 3092: 3088: 3084: 3078: 3063: 3059: 3052: 3044: 3038: 3035:. p. 3. 3034: 3030: 3026: 3020: 3013: 3008: 3006: 2997: 2991: 2987: 2983: 2979: 2973: 2964: 2957: 2953: 2947: 2943: 2939: 2932: 2924: 2918: 2915:. p. 3. 2914: 2910: 2906: 2900: 2893: 2888: 2881: 2870:September 26, 2865: 2861: 2855: 2851: 2840: 2837: 2835: 2834: 2830: 2828: 2825: 2823: 2820: 2818: 2815: 2813: 2810: 2808: 2805: 2803: 2800: 2798: 2795: 2793: 2792:Invalid proof 2790: 2788: 2785: 2784: 2779: 2773: 2768: 2765: 2754: 2747: 2741: 2738: 2734: 2730: 2726: 2722: 2718: 2712: 2702: 2700: 2699: 2694: 2690: 2685: 2675: 2673: 2669: 2665: 2661: 2657: 2651: 2647: 2637: 2635: 2631: 2627: 2622: 2620: 2616: 2612: 2608: 2605:Proofs using 2602: 2598: 2588: 2586: 2585:scatter plots 2582: 2578: 2574: 2570: 2569: 2563: 2559: 2555: 2551: 2547: 2546:data analysis 2541: 2531: 2529: 2519: 2516: 2507: 2498: 2496: 2492: 2488: 2487:number theory 2482: 2472: 2470: 2458: 2453: 2446: 2441: 2437: 2430: 2425: 2424: 2423: 2421: 2417: 2413: 2398: 2396: 2392: 2388: 2384: 2380: 2376: 2370: 2360: 2358: 2354: 2352: 2348: 2343: 2341: 2337: 2333: 2323: 2320: 2317:proof of the 2313: 2303: 2301: 2297: 2293: 2289: 2285: 2281: 2277: 2271: 2247: 2242: 2238: 2217: 2214: 2209: 2203: 2197: 2191: 2185: 2179: 2172: 2166: 2142: 2137: 2134: 2111: 2104: 2098: 2095: 2072: 2065: 2040: 2035: 2032: 2029: 2026: 2003: 1996: 1985: 1984: 1983: 1966: 1959: 1948: 1930: 1920: 1902: 1898: 1889: 1885: 1882: 1877: 1871: 1861: 1859: 1855: 1851: 1845: 1835: 1833: 1829: 1825: 1821: 1816: 1812: 1810: 1806: 1800: 1790: 1788: 1784: 1779: 1763: 1759: 1750: 1746: 1723: 1719: 1710: 1707: 1704: 1700: 1679: 1657: 1653: 1644: 1640: 1617: 1613: 1604: 1600: 1577: 1573: 1569: 1566: 1563: 1558: 1554: 1544: 1540: 1530: 1528: 1521: 1511: 1509: 1505: 1501: 1497: 1491: 1481: 1479: 1461: 1433: 1423: 1419: 1415: 1411: 1407: 1403: 1399: 1395: 1391: 1387: 1383: 1379: 1375: 1371: 1367: 1363: 1359: 1355: 1351: 1335: 1332: 1327: 1322: 1314: 1310: 1306: 1288: 1285: 1280: 1275: 1251: 1242:Suppose that 1241: 1240: 1239: 1237: 1219: 1209: 1205: 1204: 1197: 1172: 1164: 1147: 1143: 1120: 1116: 1108:is odd. Thus 1095: 1092: 1089: 1086: 1081: 1077: 1056: 1036: 1028: 1027: 1026: 1012: 990: 986: 965: 956: 954: 950: 946: 943: 939: 935: 931: 928: 923: 913: 906: 899: 894: 891: 886: 882: 875: 871: 864: 860: 853: 845: 841: 837: 825: 817: 813: 806: 799: 794: 791: 786: 767: 759: 754: 751: 750: 749: 745: 737: 733: 728: 722: 713: 710: 703: 699: 693: 688: 684: 677: 673: 666: 662: 655: 651: 647: 644: 639: 632: 628: 621: 617: 614: 613: 612: 609: 605:belonging to 603: 596: 592: 585: 580: 575: 573: 569: 565: 561: 557: 553: 547: 537: 535: 531: 523: 519: 515: 512:). Therefore 511: 507: 503: 499: 495: 492: +  491: 487: 483: 479: 475: 471: 467: 463: 459: 455: 454: 453: 451: 448: 442: 427: 425: 424: 419: 415: 410: 408: 404: 400: 396: 392: 388: 384: 378: 376: 372: 367: 363: 359: 355: 350: 347: 337: 335: 331: 327: 323: 318: 316: 312: 308: 304: 300: 296: 292: 287: 283: 279: 274: 272: 271:prime numbers 268: 264: 260: 259:number theory 256: 252: 248: 247: 242: 238: 234: 230: 226: 221: 219: 215: 211: 207: 203: 199: 195: 189: 187: 183: 179: 175: 169: 159: 157: 153: 149: 145: 141: 137: 133: 129: 125: 124:formal proofs 121: 118: 114: 110: 105: 103: 99: 95: 91: 87: 83: 79: 75: 71: 67: 63: 60: 56: 48: 47: 42: 38: 34: 30: 19: 6020:Proof theory 5859:Substitution 5679:Mathematical 5604:Major fields 5529: 5327:Ultraproduct 5174:Model theory 5139:Independence 5075:Formal proof 5067:Proof theory 5050: 5023: 4980:real numbers 4952:second-order 4863:Substitution 4740:Metalanguage 4681:conservative 4654:Axiom schema 4598:Constructive 4568:Morse–Kelley 4534:Set theories 4513:Aleph number 4506:inaccessible 4412:Grothendieck 4296:intersection 4183:Higher-order 4171:Second-order 4117:Truth tables 4074:Venn diagram 3857:Formal proof 3733: 3713: 3690: 3681: 3678:Gold, Bonnie 3658: 3654:Franklin, J. 3644: 3640: 3606: 3580:. Retrieved 3576: 3566: 3531: 3525: 3512: 3504: 3484: 3476: 3467: 3464:the original 3454: 3445: 3425: 3408: 3397: 3387: 3382: 3371: 3363: 3358: 3350: 3345: 3326: 3321: 3314: 3295: 3290: 3283: 3270: 3251: 3240: 3231: 3222: 3210:. Retrieved 3208:. p. 12 3205: 3192: 3169: 3156: 3124: 3118: 3112: 3104: 3086: 3077: 3065:. Retrieved 3061: 3051: 3028: 3019: 2981: 2978:Hacking, Ian 2972: 2963: 2955: 2937: 2931: 2908: 2899: 2890: 2886: 2880: 2868:. Retrieved 2854: 2831: 2728: 2720: 2716: 2714: 2697: 2681: 2653: 2646:Psychologism 2623: 2604: 2566: 2561: 2557: 2543: 2525: 2512: 2484: 2466: 2409: 2406:Visual proof 2372: 2355: 2344: 2329: 2315: 2280:cryptography 2273: 1887: 1883: 1873: 1852:between two 1847: 1817: 1813: 1802: 1783:transitivity 1780: 1545: 1542: 1523: 1493: 1451: 1421: 1417: 1413: 1409: 1405: 1401: 1397: 1393: 1389: 1385: 1381: 1377: 1373: 1369: 1361: 1357: 1353: 1349: 1308: 1304: 1201: 1199: 1162: 957: 952: 948: 937: 933: 925: 911: 904: 897: 892: 884: 880: 873: 869: 862: 858: 851: 843: 839: 835: 823: 815: 811: 804: 797: 792: 784: 765: 757: 752: 743: 735: 731: 720: 716: 708: 701: 697: 694: 686: 682: 675: 671: 664: 660: 653: 649: 645: 637: 635:is true for 630: 626: 619: 615: 607: 601: 594: 590: 583: 576: 549: 527: 517: 513: 509: 505: 501: 497: 493: 489: 485: 481: 477: 473: 469: 465: 461: 457: 444: 441:Direct proof 435:Direct proof 421: 411: 379: 371:proof theory 358:formal proof 351: 343: 322:proof theory 319: 302: 275: 257:also covers 254: 245: 222: 190: 185: 181: 177: 173: 171: 132:proof theory 106: 97: 54: 52: 44: 29: 5974:WikiProject 5844:Proposition 5839:Probability 5792:Description 5733:Foundations 5437:Type theory 5385:undecidable 5317:Truth value 5204:equivalence 4883:non-logical 4496:Enumeration 4486:Isomorphism 4433:cardinality 4417:Von Neumann 4382:Ultrafilter 4347:Uncountable 4281:equivalence 4198:Quantifiers 4188:Fixed-point 4157:First-order 4037:Consistency 4022:Proposition 3999:Traditional 3970:Lindström's 3960:Compactness 3902:Type theory 3847:Cardinality 3785:Wikiversity 3582:October 15, 3388:statistical 3212:October 20, 3091:Brooks/Cole 3067:October 20, 2740:Paul Halmos 2723:, which is 2611:probability 2562:assumptions 2554:probability 740:represent " 520:has 2 as a 5999:Categories 5904:Set theory 5802:Linguistic 5797:Entailment 5787:Definition 5755:Consequent 5750:Antecedent 5248:elementary 4941:arithmetic 4809:Quantifier 4787:functional 4659:Expression 4377:Transitive 4321:identities 4306:complement 4239:hereditary 4222:Set theory 3491:Icon Books 3366:94:165–86. 3353:79:252–63. 2846:References 2701:argument. 1890:such that 611:such that 564:infinitely 504: = 2( 418:Paul Erdős 305:(1000) by 286:Al-Hashimi 267:irrational 214:Theaetetus 166:See also: 102:conjecture 37:P. Oxy. 29 5935:Fallacies 5930:Paradoxes 5920:Logicians 5854:Statement 5849:Reference 5814:Induction 5777:Deduction 5740:Abduction 5710:Metalogic 5657:Classical 5621:Inference 5519:Supertask 5422:Recursion 5380:decidable 5214:saturated 5192:of models 5115:deductive 5110:axiomatic 5030:Hilbert's 5017:Euclidean 4998:canonical 4921:axiomatic 4853:Signature 4782:Predicate 4671:Extension 4593:Ackermann 4518:Operation 4397:Universal 4387:Recursive 4362:Singleton 4357:Inhabited 4342:Countable 4332:Types of 4316:power set 4286:partition 4203:Predicate 4149:Predicate 4064:Syllogism 4054:Soundness 4027:Inference 4017:Tautology 3919:paradoxes 3602:Pólya, G. 3185:p. 3 3149:121416910 2980:(1984) . 2907:(2005) . 2892:obtained. 2733:tombstone 2693:Descartes 2689:certainty 2615:certainty 1850:bijection 1760:φ 1756:⇒ 1747:φ 1720:φ 1716:⇒ 1708:− 1701:φ 1680:… 1654:φ 1650:⇒ 1641:φ 1614:φ 1610:⇒ 1601:φ 1574:φ 1567:… 1555:φ 1093:⋅ 1025:is even: 748:is odd": 552:deduction 496: = 2 391:synthetic 307:Al-Karaji 303:Al-Fakhri 218:Aristotle 186:probieren 122:. Purely 90:empirical 82:inference 70:logically 59:deductive 5969:Category 5869:Validity 5770:Antinomy 5698:Theories 5662:Informal 5504:Logicism 5497:timeline 5473:Concrete 5332:Validity 5302:T-schema 5295:Kripke's 5290:Tarski's 5285:semantic 5275:Strength 5224:submodel 5219:spectrum 5187:function 5035:Tarski's 5024:Elements 5011:geometry 4967:Robinson 4888:variable 4873:function 4846:spectrum 4836:Sentence 4792:variable 4735:Language 4688:Relation 4649:Automata 4639:Alphabet 4623:language 4477:-jection 4455:codomain 4441:Function 4402:Universe 4372:Infinite 4276:Relation 4059:Validity 4049:Argument 3947:theorem, 3647:: 373–88 3604:(1954), 3558:23084607 3424:(2002). 3259:Archived 2750:See also 2717:"Q.E.D." 2634:evidence 2420:triangle 1478:fraction 1376:, where 1315:. Thus, 1029:Suppose 878:implies 856:is odd ( 820:), then 809:is odd ( 795:For any 789:is true. 691:is true. 450:integers 387:analytic 366:formulas 346:argument 255:Elements 246:Elements 194:geometry 117:rigorous 74:theorems 62:argument 46:Elements 5984:changes 5976: ( 5834:Premise 5765:Paradox 5595:History 5590:Outline 5446:Related 5243:Diagram 5141: ( 5120:Hilbert 5105:Systems 5100:Theorem 4978:of the 4923:systems 4703:Formula 4698:Grammar 4614: ( 4558:General 4271:Forcing 4256:Element 4176:Monadic 3951:paradox 3892:Theorem 3828:General 3168:(ed.), 3129:Bibcode 2684:Spinoza 2656:Leibniz 2381:to the 1986:Either 1785:of the 867:). So 782:. Thus 729:. Let 560:implies 530:closure 320:Modern 210:Eudoxus 182:provare 174:probare 5886:topics 5672:Reason 5650:Logics 5641:Syntax 5209:finite 4972:Skolem 4925:  4900:Theory 4868:Symbol 4858:String 4841:atomic 4718:ground 4713:closed 4708:atomic 4664:ground 4627:syntax 4523:binary 4450:domain 4367:Finite 4132:finite 3990:Logics 3949:  3897:Theory 3781:course 3777:lesson 3741:  3720:  3701:  3684:. MAA. 3666:  3624:  3556:  3497:  3438:  3333:  3302:  3176:  3147:  3097:  3039:  2992:  2948:  2919:  2737:eponym 2711:Q.E.D. 2698:cogito 2664:Carnap 2662:, and 2379:Euclid 2332:axioms 2286:, and 2055:), or 1947:Euclid 1303:where 1234:is an 947:: "if 930:infers 770:, and 581:: Let 522:factor 253:, the 237:axioms 225:Euclid 202:Thales 178:probar 78:axioms 64:for a 41:Euclid 5913:other 5878:Lists 5864:Truth 5631:Proof 5579:Logic 5199:Model 4947:Peano 4804:Proof 4644:Arity 4573:Naive 4460:image 4392:Fuzzy 4352:Empty 4301:union 4246:Class 3887:Model 3877:Lemma 3835:Axiom 3783:from 3695:Wiley 3554:S2CID 3522:(PDF) 3469:time. 3325:[ 3294:[ 3202:(PDF) 3145:S2CID 2725:Latin 2660:Frege 2558:using 2548:, or 1917:is a 1476:as a 1404:, so 1388:) = 4 978:, if 953:not p 951:then 949:not q 936:then 848:, so 801:, if 695:Then 403:Quine 293:. An 282:Iraqi 109:logic 57:is a 5978:talk 5824:Name 5809:Form 5322:Type 5125:list 4929:list 4906:list 4895:Term 4829:rank 4723:open 4617:list 4429:Maps 4334:sets 4193:Free 4163:list 3913:list 3840:list 3739:ISBN 3718:ISBN 3699:ISBN 3664:ISBN 3622:ISBN 3584:2009 3495:ISBN 3436:ISBN 3331:ISBN 3300:ISBN 3274:See 3214:2019 3174:ISBN 3095:ISBN 3069:2019 3037:ISBN 2990:ISBN 2946:ISBN 2917:ISBN 2872:2008 2727:for 2648:and 2599:and 2127:and 1886:and 1854:sets 1830:for 1738:and 1420:and 1412:and 1384:= (2 1307:and 893:Thus 793:(ii) 755:For 725:are 646:(ii) 484:and 472:and 460:and 447:even 395:Kant 356:. A 332:and 297:for 235:and 5720:Set 5009:of 4991:of 4939:of 4471:Sur 4445:Map 4252:Ur- 4234:Set 3612:hdl 3544:hdl 3536:doi 3137:doi 3125:500 2579:in 2290:or 1396:= 2 1372:= 2 955:". 887:+1) 865:+1) 787:(1) 760:= 1 753:(i) 727:odd 689:+1) 656:+1) 640:= 1 622:(1) 616:(i) 389:or 265:is 98:all 43:'s 6001:: 5395:NP 5019:: 5013:: 4943:: 4620:), 4475:Bi 4467:In 3775:A 3697:, 3693:, 3645:45 3643:, 3639:, 3620:, 3575:. 3552:. 3542:. 3532:49 3530:. 3524:. 3503:. 3493:. 3489:. 3444:. 3434:. 3430:. 3420:; 3416:; 3204:. 3143:, 3135:, 3123:, 3103:. 3060:. 3004:^ 2988:. 2984:. 2954:. 2940:. 2889:. 2862:. 2746:. 2695:' 2674:. 2658:, 2621:. 2422:. 2353:. 2342:. 2282:, 1811:. 1789:. 1778:. 1692:, 1672:, 1632:, 1352:= 1238:: 1163:is 850:2( 834:(2 822:(2 762:, 574:. 536:. 393:. 336:. 317:. 273:. 158:. 142:, 53:A 5980:) 5571:e 5564:t 5557:v 5475:/ 5390:P 5145:) 4931:) 4927:( 4824:∀ 4819:! 4814:∃ 4775:= 4770:↔ 4765:→ 4760:∧ 4755:∨ 4750:¬ 4473:/ 4469:/ 4443:/ 4254:) 4250:( 4137:∞ 4127:3 3915:) 3813:e 3806:t 3799:v 3748:. 3727:. 3708:. 3673:. 3649:. 3631:. 3614:: 3586:. 3560:. 3546:: 3538:: 3339:. 3308:. 3278:. 3216:. 3139:: 3131:: 3071:. 3045:. 2998:. 2925:. 2874:. 2248:. 2243:b 2239:a 2218:2 2215:= 2210:2 2204:2 2198:= 2192:2 2186:) 2180:2 2173:2 2167:( 2143:2 2138:= 2135:b 2112:2 2105:2 2099:= 2096:a 2073:2 2066:2 2041:2 2036:= 2033:b 2030:= 2027:a 2004:2 1997:2 1967:2 1960:2 1931:2 1903:b 1899:a 1888:b 1884:a 1764:1 1751:n 1724:n 1711:1 1705:n 1658:3 1645:2 1618:2 1605:1 1578:n 1570:, 1564:, 1559:1 1462:2 1434:2 1422:b 1418:a 1414:b 1410:a 1406:b 1402:b 1398:c 1394:b 1390:c 1386:c 1382:b 1378:c 1374:c 1370:a 1362:a 1358:a 1354:a 1350:b 1336:a 1333:= 1328:2 1323:b 1309:b 1305:a 1289:b 1286:a 1281:= 1276:2 1252:2 1220:2 1173:x 1148:2 1144:x 1121:2 1117:x 1096:x 1090:x 1087:= 1082:2 1078:x 1057:x 1037:x 1013:x 991:2 987:x 966:x 938:q 934:p 908:. 905:n 898:n 896:2 889:. 885:n 883:( 881:P 876:) 874:n 872:( 870:P 863:n 861:( 859:P 852:n 844:n 840:n 836:n 830:2 824:n 818:) 816:n 814:( 812:P 805:n 803:2 798:n 785:P 780:2 776:1 772:1 766:n 764:2 758:n 744:n 742:2 738:) 736:n 734:( 732:P 721:n 719:2 712:. 709:n 704:) 702:n 700:( 698:P 687:n 685:( 683:P 678:) 676:n 674:( 672:P 667:) 665:n 663:( 661:P 654:n 652:( 650:P 642:. 638:n 633:) 631:n 629:( 627:P 620:P 608:N 602:n 597:) 595:n 593:( 591:P 584:N 518:y 516:+ 514:x 510:b 508:+ 506:a 502:b 498:a 494:y 490:x 486:b 482:a 478:b 474:y 470:a 466:x 462:y 458:x 20:)

Index

Theorem-proving

P. Oxy. 29
Euclid
Elements
deductive
argument
mathematical statement
logically
theorems
axioms
inference
deductive reasoning
empirical
inductive reasoning
conjecture
logic
natural language
rigorous
informal logic
formal proofs
symbolic language
proof theory
formal and informal proofs
mathematical practice
quasi-empiricism in mathematics
folk mathematics
philosophy of mathematics
mathematics as a language
History of logic

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