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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.
2448: 22: 3751: 3496:...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'... 2497: 5950: 2749: 2462:, 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. 3437:
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
3178:: "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." 357:
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.
177:(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. 3767: 2151: 2435: 2384:. Early pioneers of these methods intended the work ultimately to be resolved into a classical proof-theorem framework, e.g. the early development of 238:, 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 2488:, could only be proved using "higher" mathematics. However, over time, many of these results have been reproved using only elementary techniques. 551:
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
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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.
209:(384–322 BCE) said definitions should describe the concept being defined in terms of other concepts already known. 202: 3931: 38:, a textbook used for millennia to teach proof-writing techniques. The diagram accompanies Book II, Proposition 5. 5894: 5819: 5601: 5504: 5453: 5350: 4848: 4809: 4286: 3015: 2787: 2777: 2646: 2517:
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
3163:, Studies in Logic and the Foundations of Mathematics, vol. 137, Elsevier, pp. 1–78, 2340:(ZFC), the standard system of set theory in mathematics (assuming that ZFC is consistent); see 5954: 5925: 5920: 5910: 5844: 5772: 5657: 5463: 5270: 5080: 5070: 4962: 4843: 4678: 4654: 4435: 4419: 4324: 4301: 4178: 4147: 4112: 4007: 3842: 3729: 3708: 3689: 3654: 3612: 3485: 3426: 3321: 3290: 3164: 3085: 3027: 2980: 2936: 2932: 2907: 2754: 2662: 2616: 2591: 2540: 2530: 2365: 2260: 1871: 1844: 1799: 1224: 918: 279: 255: 198: 186: 3628:"What Do Mathematicians Want? Probabilistic Proofs and the Epistemic Goals of Mathematicians" 3049:"The genesis of proof in ancient Greece The pedagogical implications of a Husserlian reading" 165:(to test). Related modern words are English "probe", "probation", and "probability", Spanish 5859: 5585: 5580: 5477: 5472: 5365: 5322: 5144: 5105: 5100: 5085: 4911: 4868: 4765: 4563: 4513: 4087: 4049: 3685: 3602: 3534: 3526: 3175: 3127: 2563: 2481: 2471: 2385: 2266: 2224: 1666: 1492: 1484: 1405:
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
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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
5824: 5755: 5090: 3882: 3081: 2674: 2535:"Statistical proof" from data refers to the application of statistics, 2329:, which is neither provable nor refutable from the remaining axioms of 1301: 510: 438: 62: 5662: 3780: 3627: 2727: 2701: 2654: 2369: 1937: 1499:
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
3256:, University of Warwick Glossary of Mathematical Terminology 2878:
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
169:(to smell or taste, or sometimes touch or test), Italian 5538: 3310:
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).
1722:{\displaystyle \varphi _{n-1}\Rightarrow \varphi _{n}} 1389:. But then, by the same argument as before, 2 divides 390:, believed mathematical proofs are synthetic, whereas 127:
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.
341:The concept of proof is formalized in the field of 3473: 3267:Four color theorem#Simplification and verification 2678:statements outside of mathematics, but having the 2354:Heuristic mathematics and experimental mathematics 2243: 2213: 2140: 2110: 2071: 2038: 2002: 1965: 1928: 1900: 1761: 1721: 1675: 1655: 1615: 1575: 1457: 1429: 1329: 1284: 1247: 1215: 1166: 1143: 1116: 1089: 1050: 1030: 1006: 986: 959: 1576:{\displaystyle \varphi _{1},\ldots ,\varphi _{n}} 3320:] (in German). Springer-Verlag. p. 28. 3289:] (in German). Springer-Verlag. p. 26. 2425:Visual proof for the (3,4,5) triangle as in the 1413:have no common factor, so we must conclude that 821:to an odd number results in an odd number. But 2855:"One of the Oldest Extant Diagrams from Euclid" 559:, which can be used, for example, to prove the 3155:(1998), "An introduction to proof theory", in 2608:. Inductive logic should not be confused with 2221:, which is thus a rational number of the form 1825:) are as good as genuine mathematical proofs. 453:. Since they are even, they can be written as 100:expressed in mathematical symbols, along with 5554: 3796: 3003:The History and Concept of Mathematical Proof 2947:Definition 3.1. Proof: An Informal Definition 8: 2582:Inductive logic proofs and Bayesian analysis 1936:is irrational (an easy proof is known since 1354: 2010:is a rational number and we are done (take 1865:A nonconstructive proof establishes that a 827: − 1) + 2 = 2 521:under addition and multiplication, and the 258:and a proof that there are infinitely many 28:, one of the oldest surviving fragments of 5872: 5637: 5561: 5547: 5539: 4622: 4217: 3985: 3803: 3789: 3781: 3197:Universität Zürich – Theologische Fakultät 3111:Annals of the New York Academy of Sciences 3606: 3538: 3418:Indra's Pearls: The Vision of Felix Klein 2458:Some illusory visual proofs, such as the 2232: 2226: 2199: 2192: 2180: 2168: 2161: 2153: 2131: 2123: 2111:{\displaystyle a={\sqrt {2}}^{\sqrt {2}}} 2100: 2093: 2084: 2061: 2054: 2051: 2029: 2015: 1992: 1985: 1982: 1955: 1948: 1945: 1919: 1917: 1892: 1886: 1753: 1740: 1734: 1713: 1694: 1688: 1668: 1647: 1634: 1628: 1607: 1594: 1588: 1567: 1548: 1542: 1448: 1446: 1420: 1418: 1314: 1309: 1272: 1262: 1260: 1238: 1236: 1206: 1204: 1159: 1135: 1129: 1108: 1102: 1069: 1063: 1043: 1023: 999: 978: 972: 952: 577:} be the set of natural numbers, and let 212:Mathematical proof was revolutionized by 2998: 2996: 1487:, for instance, proved the existence of 1154:even, the supposition must be false, so 398:" that such a distinction is untenable. 189:, and one of its greatest achievements. 3005:, Steven G. Krantz. 1. February 5, 2007 2842: 2480:to refer to proofs that make no use of 2415: 2380:beyond the proof-theorem framework, in 2072:{\displaystyle {\sqrt {2}}^{\sqrt {2}}} 2003:{\displaystyle {\sqrt {2}}^{\sqrt {2}}} 1966:{\displaystyle {\sqrt {2}}^{\sqrt {2}}} 1285:{\displaystyle {\sqrt {2}}={a \over b}} 763:is odd, since it leaves a remainder of 561:irrationality of the square root of two 3705:How to Prove It: A Structured Approach 3564:"Introduction to the Two-Column Proof" 2513:Colloquial use of "mathematical proof" 2348:Gödel's (first) incompleteness theorem 2255:Statistical proofs in pure mathematics 1537:In order to prove that the statements 1495:. It can also be used to construct a 161:The word "proof" comes from the Latin 57:, showing that the stated assumptions 3650:Proof in Mathematics: An Introduction 2342:List of statements undecidable in ZFC 338:vague or incomplete may be rejected. 313:treats proofs as inductively defined 16:Reasoning for mathematical statements 7: 2543:to infer propositions regarding the 2500:A two-column proof published in 1913 2388:, which was ultimately so resolved. 265:Further advances also took place in 73:. Proofs are examples of exhaustive 5736:Analytic and synthetic propositions 5607:Formal semantics (natural language) 3598:Mathematics and Plausible Reasoning 3451:"A Note on the History of Fractals" 2720:"that which was to be demonstrated" 2673:Philosopher-mathematicians such as 2364:While early mathematicians such as 220:still in use today. It starts with 69:, along with the accepted rules of 3518:Educational Studies in Mathematics 3132:10.1111/j.1749-6632.1987.tb37206.x 2876:Clapham, C. & Nicholson, J.N. 2824:What the Tortoise Said to Achilles 1441:To paraphrase: if one could write 1381:. Dividing both sides by 2 yields 891:is odd, for all positive integers 469:, respectively, for some integers 14: 3188:Quine, Willard Van Orman (1961). 817:must also be odd, because adding 5948: 5522: 3749: 2857:. University of British Columbia 2761: 2747: 2446: 2434: 2418: 695:is true for all natural numbers 401:Proofs may be admired for their 366:not provable within the system. 2929:Discrete Mathematics with Proof 2559:mathematical methods of physics 2039:{\displaystyle a=b={\sqrt {2}}} 529:Proof by mathematical induction 133:quasi-empiricism in mathematics 3707:, Cambridge University Press, 3601:, Princeton University Press, 3472:Lesmoir-Gordon, Nigel (2000). 3018:; Kneale, Martha (May 1985) . 2079:is irrational so we can write 1746: 1706: 1640: 1600: 1337:. Squaring both sides yields 2 1330:{\displaystyle b{\sqrt {2}}=a} 1090:{\displaystyle x^{2}=x\cdot x} 388:analytic–synthetic distinction 269:. In the 10th century CE, the 216:(300 BCE), who introduced the 1: 5483:History of mathematical logic 3342:American Mathematical Monthly 2562:applied to analyze data in a 2141:{\displaystyle b={\sqrt {2}}} 831: + 1 = 2( 815: − 1) + 2 250:, including a proof that the 5408:Primitive recursive function 3671:; Simons, Rogers A. (2008). 3508:Herbst, Patricio G. (2002). 3476:Introducing Fractal Geometry 2706:Sometimes, the abbreviation 2627:or information is acquired. 2604:, and may be less than full 2525:Statistical proof using data 2291:Statistical proof using data 1349:is even, which implies that 267:medieval Islamic mathematics 81:arguments or non-exhaustive 2927:Gossett, Eric (July 2009). 2798:List of mathematical proofs 2409:in the case of the (3,4,5) 2279:probabilistic number theory 1929:{\displaystyle {\sqrt {2}}} 1458:{\displaystyle {\sqrt {2}}} 1430:{\displaystyle {\sqrt {2}}} 1300:are non-zero integers with 1248:{\displaystyle {\sqrt {2}}} 1216:{\displaystyle {\sqrt {2}}} 445:Consider two even integers 298:, who used it to prove the 6034: 4472:Schröder–Bernstein theorem 4199:Monadic predicate calculus 3858:Foundations of mathematics 3423:Cambridge University Press 3252:February 18, 2012, at the 3190:"Two Dogmas of Empiricism" 2977:Cambridge University Press 2699: 2634: 2585: 2528: 2469: 2357: 2300: 2258: 1858: 1832: 1787: 1506: 1476: 1397:must be even. However, if 1182: 908: 532: 427: 154: 125:formal and informal proofs 123:. The distinction between 5943: 5820:Necessity and sufficiency 5576: 5518: 5505:Philosophy of mathematics 5454:Automated theorem proving 4625: 4579:Von Neumann–Bernays–Gödel 4220: 3722:Hammack, Richard (2018), 3381:proof"" (Derogatory use.) 2788:List of incomplete proofs 2778:Automated theorem proving 2712:"quod erat demonstrandum" 2621:assessment of likelihoods 2368:did not use proofs, from 557:proof by infinite descent 187:ancient Greek mathematics 145:mathematics as a language 141:philosophy of mathematics 6001:Mathematical terminology 3161:Handbook of Proof Theory 3020:The development of logic 2726:" or "halmos" after its 2631:Proofs as mental objects 2382:experimental mathematics 2374:foundational mathematics 2360:Experimental mathematics 2297:Computer-assisted proofs 1849:double counting argument 1437:is an irrational number. 1355:#Proof by contraposition 934:contrapositive statement 396:Two Dogmas of Empiricism 5155:Self-verifying theories 4976:Tarski's axiomatization 3927:Tarski's undefinability 3922:incompleteness theorems 3608:2027/mdp.39015008206248 3531:10.1023/A:1020264906740 3024:Oxford University Press 2735:(220E(hex) = 8718(dec)) 2623:of hypotheses when new 2615:Bayesian analysis uses 2303:Computer-assisted proof 2287:mathematical statistics 1912:. This proof uses that 1819:probabilistic algorithm 916:Proof by contraposition 905:Proof by contraposition 5529:Mathematics portal 5140:Proof of impossibility 4788:propositional variable 4098:Propositional calculus 3568:onemathematicalcat.org 3457:on February 15, 2009. 2610:mathematical induction 2501: 2317:Undecidable statements 2283:analytic number theory 2245: 2244:{\displaystyle a^{b}.} 2215: 2142: 2112: 2073: 2040: 2004: 1967: 1930: 1902: 1763: 1723: 1677: 1676:{\displaystyle \dots } 1657: 1617: 1577: 1529:Closed chain inference 1522:Closed chain inference 1489:transcendental numbers 1459: 1431: 1331: 1286: 1249: 1217: 1185:Proof by contradiction 1179:Proof by contradiction 1168: 1145: 1124:is not even. Thus, if 1118: 1091: 1052: 1032: 1008: 988: 961: 929:" by establishing the 535:Mathematical induction 364:undecidable statements 323:Non-Euclidean geometry 290:was introduced in the 55:mathematical statement 39: 5955:Philosophy portal 5398:Kolmogorov complexity 5351:Computably enumerable 5251:Model complete theory 5043:Principia Mathematica 4103:Propositional formula 3932:Banach–Tarski paradox 3703:Velleman, D. (2006), 3355:Journal of Philosophy 2933:John Wiley & Sons 2808:Proof by intimidation 2803:Nonconstructive proof 2619:to update a person's 2506:mathematical exercise 2499: 2460:missing square puzzle 2246: 2216: 2143: 2113: 2074: 2041: 2005: 1968: 1931: 1903: 1901:{\displaystyle a^{b}} 1861:Nonconstructive proof 1855:Nonconstructive proof 1764: 1724: 1678: 1658: 1618: 1578: 1479:Proof by construction 1473:Proof by construction 1460: 1432: 1332: 1287: 1250: 1218: 1197:logical contradiction 1169: 1146: 1144:{\displaystyle x^{2}} 1119: 1117:{\displaystyle x^{2}} 1092: 1053: 1033: 1009: 989: 987:{\displaystyle x^{2}} 962: 669:is true implies that 523:distributive property 386:, who introduced the 232:. Euclid's book, the 173:(to try), and German 151:History and etymology 129:mathematical practice 24: 6016:Sources of knowledge 5346:Church–Turing thesis 5333:Computability theory 4542:continuum hypothesis 4060:Square of opposition 3918:Gödel's completeness 3758:at Wikimedia Commons 3647:; Daoud, A. (2011), 3626:Fallis, Don (2002), 3174:. See in particular 2896:Cupillari, Antonella 2830:Zero-knowledge proof 2813:Termination analysis 2519:mathematical objects 2486:prime number theorem 2378:mathematical objects 2269:, such as involving 2225: 2152: 2122: 2083: 2050: 2014: 1981: 1944: 1916: 1885: 1790:Probabilistic method 1778:material conditional 1733: 1687: 1667: 1627: 1587: 1541: 1445: 1417: 1308: 1259: 1235: 1203: 1192:reductio ad absurdum 1158: 1128: 1101: 1062: 1042: 1022: 998: 971: 951: 931:logically equivalent 412:Proofs from THE BOOK 405:. The mathematician 394:argued in his 1951 " 319:Axiomatic set theory 288:arithmetic sequences 195:Hippocrates of Chios 6006:Mathematical proofs 5617:Philosophy of logic 5500:Mathematical object 5391:P versus NP problem 5356:Computable function 5150:Reverse mathematics 5076:Logical consequence 4953:primitive recursive 4948:elementary function 4721:Free/bound variable 4574:Tarski–Grothendieck 4093:Logical connectives 4023:Logical equivalence 3873:Logical consequence 3770:about proofs, in a 3728:, Richard Hammack, 3124:1987NYASA.500..253M 3053:Archive ouverte HAL 2793:List of long proofs 2659:language of thought 2641:Language of thought 2568:observational study 2407:Pythagorean theorem 2403:proof without words 1867:mathematical object 1835:Combinatorial proof 1829:Combinatorial proof 1784:Probabilistic proof 1509:Proof by exhaustion 1503:Proof by exhaustion 1491:by constructing an 1357:). So we can write 545:inductive reasoning 403:mathematical beauty 240:Pythagorean theorem 115:, written fully in 83:inductive reasoning 75:deductive reasoning 5996:Mathematical logic 5916:Rules of inference 5885:Mathematical logic 5627:Semantics of logic 5298:Transfer principle 5261:Semantics of logic 5246:Categorical theory 5222:Non-standard model 4736:Logical connective 3863:Information theory 3812:Mathematical logic 3756:Mathematical proof 3680:Solow, D. (2004), 3632:Logique et Analyse 3562:Dr. Fisher Burns. 3247:Proof by induction 2902:(Third ed.). 2818:Thought experiment 2769:Mathematics portal 2572:physical cosmology 2502: 2331:Euclidean geometry 2327:parallel postulate 2310:four color theorem 2241: 2211: 2148:. This then gives 2138: 2108: 2069: 2036: 2000: 1963: 1926: 1898: 1872:irrational numbers 1815:Mertens conjecture 1811:Collatz conjecture 1800:existence theorems 1796:probability theory 1759: 1719: 1673: 1653: 1613: 1573: 1516:four color theorem 1455: 1427: 1327: 1282: 1245: 1213: 1164: 1141: 1114: 1087: 1048: 1038:is not even. Then 1028: 1004: 984: 957: 921:the statement "if 575:= {1, 2, 3, 4, ... 477:. Then the sum is 343:mathematical logic 329:Nature and purpose 302:and properties of 280:irrational numbers 252:square root of two 201:(408–355 BCE) and 193:(624–546 BCE) and 44:mathematical proof 40: 5983: 5982: 5939: 5938: 5773:Deductive closure 5719: 5718: 5658:Critical thinking 5536: 5535: 5468:Abstract category 5271:Theories of truth 5081:Rule of inference 5071:Natural deduction 5052: 5051: 4597: 4596: 4302:Cartesian product 4207: 4206: 4113:Many-valued logic 4088:Boolean functions 3971:Russell's paradox 3946:diagonal argument 3843:First-order logic 3754:Media related to 3735:978-0-9894721-3-5 3714:978-0-521-67599-4 3695:978-0-471-68058-1 3660:978-0-646-54509-7 3491:978-1-84046-123-7 3432:978-0-521-35253-6 3405:Mumford, David B. 3327:978-3-662-49870-5 3296:978-3-662-58352-4 3226:Cupillari, p. 46. 3217:Cupillari, p. 20. 3170:978-0-08-053318-6 3076:(January 1990) . 3033:978-0-19-824773-9 2986:978-0-521-31803-7 2913:978-0-12-088509-1 2755:Philosophy portal 2736: 2663:empirical science 2592:Bayesian analysis 2541:Bayesian analysis 2531:Statistical proof 2429:500–200 BCE. 2366:Eudoxus of Cnidus 2293:" section below. 2289:. See also the " 2261:Statistical proof 2197: 2185: 2173: 2166: 2136: 2105: 2098: 2066: 2059: 2034: 1997: 1990: 1960: 1953: 1924: 1823:testing primality 1453: 1425: 1319: 1280: 1267: 1243: 1225:irrational number 1211: 1167:{\displaystyle x} 1051:{\displaystyle x} 1031:{\displaystyle x} 1007:{\displaystyle x} 960:{\displaystyle x} 843:+1) − 1 835:+1) − 1 647:is true whenever 304:Pascal's triangle 117:symbolic language 6023: 5953: 5952: 5951: 5873: 5638: 5602:Computer science 5563: 5556: 5549: 5540: 5527: 5526: 5478:History of logic 5473:Category of sets 5366:Decision problem 5145:Ordinal analysis 5086:Sequent calculus 4984:Boolean algebras 4924: 4923: 4898: 4869:logical/constant 4623: 4609: 4532:Zermelo–Fraenkel 4283:Set operations: 4218: 4155: 3986: 3966:Löwenheim–Skolem 3853:Formal semantics 3805: 3798: 3791: 3782: 3753: 3738: 3717: 3698: 3676: 3663: 3639: 3621: 3610: 3579: 3578: 3576: 3574: 3559: 3553: 3552: 3542: 3514: 3505: 3499: 3498: 3479: 3469: 3463: 3462: 3453:. Archived from 3447: 3441: 3440: 3409:Series, Caroline 3401: 3395: 3390: 3384: 3375: 3369: 3364: 3358: 3351: 3345: 3338: 3332: 3331: 3307: 3301: 3300: 3276: 3270: 3263: 3257: 3244: 3238: 3233: 3227: 3224: 3218: 3215: 3209: 3208: 3206: 3204: 3194: 3185: 3179: 3173: 3149: 3143: 3142: 3105: 3099: 3098: 3080:(6th ed.). 3070: 3064: 3063: 3061: 3059: 3044: 3038: 3037: 3022:(New ed.). 3012: 3006: 3000: 2991: 2990: 2965: 2959: 2956: 2950: 2949: 2924: 2918: 2917: 2892: 2886: 2885: 2873: 2867: 2866: 2864: 2862: 2847: 2771: 2766: 2765: 2757: 2752: 2751: 2750: 2734: 2564:particle physics 2492:Two-column proof 2482:complex analysis 2472:Elementary proof 2466:Elementary proof 2450: 2438: 2422: 2392:Related concepts 2386:fractal geometry 2267:pure mathematics 2250: 2248: 2247: 2242: 2237: 2236: 2220: 2218: 2217: 2212: 2204: 2203: 2198: 2193: 2187: 2186: 2181: 2179: 2175: 2174: 2169: 2167: 2162: 2147: 2145: 2144: 2139: 2137: 2132: 2117: 2115: 2114: 2109: 2107: 2106: 2101: 2099: 2094: 2078: 2076: 2075: 2070: 2068: 2067: 2062: 2060: 2055: 2045: 2043: 2042: 2037: 2035: 2030: 2009: 2007: 2006: 2001: 1999: 1998: 1993: 1991: 1986: 1972: 1970: 1969: 1964: 1962: 1961: 1956: 1954: 1949: 1940:), but not that 1935: 1933: 1932: 1927: 1925: 1920: 1907: 1905: 1904: 1899: 1897: 1896: 1768: 1766: 1765: 1760: 1758: 1757: 1745: 1744: 1728: 1726: 1725: 1720: 1718: 1717: 1705: 1704: 1682: 1680: 1679: 1674: 1662: 1660: 1659: 1654: 1652: 1651: 1639: 1638: 1622: 1620: 1619: 1614: 1612: 1611: 1599: 1598: 1582: 1580: 1579: 1574: 1572: 1571: 1553: 1552: 1493:explicit example 1485:Joseph Liouville 1464: 1462: 1461: 1456: 1454: 1449: 1436: 1434: 1433: 1428: 1426: 1421: 1336: 1334: 1333: 1328: 1320: 1315: 1302:no common factor 1291: 1289: 1288: 1283: 1281: 1273: 1268: 1263: 1254: 1252: 1251: 1246: 1244: 1239: 1222: 1220: 1219: 1214: 1212: 1207: 1173: 1171: 1170: 1165: 1150: 1148: 1147: 1142: 1140: 1139: 1123: 1121: 1120: 1115: 1113: 1112: 1096: 1094: 1093: 1088: 1074: 1073: 1057: 1055: 1054: 1049: 1037: 1035: 1034: 1029: 1013: 1011: 1010: 1005: 993: 991: 990: 985: 983: 982: 966: 964: 963: 958: 896: 890: 877: 866: 855: 844: 836: 820: 816: 808: 797: 789: 777: 770: 767:when divided by 766: 762: 758: 750: 736: 728: 713: 700: 694: 679: 668: 657: 646: 630: 623: 612: 599: 593: 587: 576: 543:, not a form of 441:is always even: 419:Methods of proof 372:proof assistants 349:is written in a 300:binomial theorem 218:axiomatic method 157:History of logic 137:folk mathematics 135:, and so-called 102:natural language 6033: 6032: 6026: 6025: 6024: 6022: 6021: 6020: 5986: 5985: 5984: 5979: 5949: 5947: 5935: 5899: 5890:Boolean algebra 5864: 5715: 5706:Metamathematics 5684: 5636: 5590: 5572: 5567: 5537: 5532: 5521: 5514: 5459:Category theory 5449:Algebraic logic 5432: 5403:Lambda calculus 5341:Church encoding 5327: 5303:Truth predicate 5159: 5125:Complete theory 5048: 4917: 4913: 4909: 4904: 4896: 4616: and  4612: 4607: 4593: 4569:New Foundations 4537:axiom of choice 4520: 4482:Gödel numbering 4422: and  4414: 4318: 4203: 4153: 4134: 4083:Boolean algebra 4069: 4033:Equiconsistency 3998:Classical logic 3975: 3956:Halting problem 3944: and  3920: and  3908: and  3907: 3902:Theorems ( 3897: 3814: 3809: 3746: 3736: 3721: 3715: 3702: 3696: 3679: 3667: 3661: 3643: 3625: 3619: 3591: 3588: 3586:Further reading 3583: 3582: 3572: 3570: 3561: 3560: 3556: 3512: 3507: 3506: 3502: 3492: 3471: 3470: 3466: 3449: 3448: 3444: 3433: 3403: 3402: 3398: 3391: 3387: 3376: 3372: 3365: 3361: 3352: 3348: 3339: 3335: 3328: 3309: 3308: 3304: 3297: 3278: 3277: 3273: 3264: 3260: 3254:Wayback Machine 3245: 3241: 3234: 3230: 3225: 3221: 3216: 3212: 3202: 3200: 3192: 3187: 3186: 3182: 3171: 3157:Buss, Samuel R. 3153:Buss, Samuel R. 3151: 3150: 3146: 3107: 3106: 3102: 3092: 3084:. p. 141. 3074:Eves, Howard W. 3072: 3071: 3067: 3057: 3055: 3046: 3045: 3041: 3034: 3016:Kneale, William 3014: 3013: 3009: 3001: 2994: 2987: 2967: 2966: 2962: 2957: 2953: 2943: 2926: 2925: 2921: 2914: 2894: 2893: 2889: 2875: 2874: 2870: 2860: 2858: 2849: 2848: 2844: 2839: 2834: 2767: 2760: 2753: 2748: 2746: 2743: 2704: 2698: 2671: 2643: 2635:Main articles: 2633: 2598:inductive logic 2594: 2588:Inductive logic 2586:Main articles: 2584: 2547:of data. While 2533: 2527: 2515: 2494: 2474: 2468: 2454: 2451: 2442: 2439: 2430: 2427:Zhoubi Suanjing 2423: 2399: 2394: 2362: 2356: 2319: 2305: 2299: 2263: 2257: 2228: 2223: 2222: 2191: 2160: 2156: 2155: 2150: 2149: 2120: 2119: 2092: 2081: 2080: 2053: 2048: 2047: 2012: 2011: 1984: 1979: 1978: 1947: 1942: 1941: 1914: 1913: 1910:rational number 1888: 1883: 1882: 1863: 1857: 1837: 1831: 1792: 1786: 1749: 1736: 1731: 1730: 1709: 1690: 1685: 1684: 1665: 1664: 1643: 1630: 1625: 1624: 1603: 1590: 1585: 1584: 1563: 1544: 1539: 1538: 1524: 1511: 1505: 1481: 1475: 1443: 1442: 1415: 1414: 1306: 1305: 1257: 1256: 1233: 1232: 1201: 1200: 1187: 1181: 1174:has to be even. 1156: 1155: 1131: 1126: 1125: 1104: 1099: 1098: 1065: 1060: 1059: 1040: 1039: 1020: 1019: 996: 995: 974: 969: 968: 949: 948: 913: 907: 892: 884: 868: 857: 846: 838: 822: 818: 810: 799: 791: 785: 772: 768: 764: 760: 752: 745: 730: 719: 707: 696: 685: 670: 659: 658:is true, i.e., 648: 637: 625: 614: 613:is true, i.e., 607: 595: 589: 578: 571: 568:natural numbers 537: 531: 432: 426: 421: 351:formal language 331: 315:data structures 284:inductive proof 230:deductive logic 222:undefined terms 159: 153: 17: 12: 11: 5: 6031: 6030: 6027: 6019: 6018: 6013: 6008: 6003: 5998: 5988: 5987: 5981: 5980: 5978: 5977: 5972: 5962: 5957: 5944: 5941: 5940: 5937: 5936: 5934: 5933: 5928: 5923: 5918: 5913: 5907: 5905: 5901: 5900: 5898: 5897: 5892: 5887: 5881: 5879: 5870: 5866: 5865: 5863: 5862: 5857: 5852: 5847: 5842: 5837: 5832: 5827: 5822: 5817: 5812: 5807: 5802: 5797: 5796: 5795: 5785: 5780: 5775: 5770: 5765: 5764: 5763: 5758: 5748: 5743: 5738: 5733: 5727: 5725: 5721: 5720: 5717: 5716: 5714: 5713: 5708: 5703: 5698: 5692: 5690: 5686: 5685: 5683: 5682: 5677: 5672: 5667: 5666: 5665: 5660: 5650: 5644: 5642: 5635: 5634: 5629: 5624: 5619: 5614: 5609: 5604: 5598: 5596: 5592: 5591: 5589: 5588: 5583: 5577: 5574: 5573: 5568: 5566: 5565: 5558: 5551: 5543: 5534: 5533: 5519: 5516: 5515: 5513: 5512: 5507: 5502: 5497: 5492: 5491: 5490: 5480: 5475: 5470: 5461: 5456: 5451: 5446: 5444:Abstract logic 5440: 5438: 5434: 5433: 5431: 5430: 5425: 5423:Turing machine 5420: 5415: 5410: 5405: 5400: 5395: 5394: 5393: 5388: 5383: 5378: 5373: 5363: 5361:Computable set 5358: 5353: 5348: 5343: 5337: 5335: 5329: 5328: 5326: 5325: 5320: 5315: 5310: 5305: 5300: 5295: 5290: 5289: 5288: 5283: 5278: 5268: 5263: 5258: 5256:Satisfiability 5253: 5248: 5243: 5242: 5241: 5231: 5230: 5229: 5219: 5218: 5217: 5212: 5207: 5202: 5197: 5187: 5186: 5185: 5180: 5173:Interpretation 5169: 5167: 5161: 5160: 5158: 5157: 5152: 5147: 5142: 5137: 5127: 5122: 5121: 5120: 5119: 5118: 5108: 5103: 5093: 5088: 5083: 5078: 5073: 5068: 5062: 5060: 5054: 5053: 5050: 5049: 5047: 5046: 5038: 5037: 5036: 5035: 5030: 5029: 5028: 5023: 5018: 4998: 4997: 4996: 4994:minimal axioms 4991: 4980: 4979: 4978: 4967: 4966: 4965: 4960: 4955: 4950: 4945: 4940: 4927: 4925: 4906: 4905: 4903: 4902: 4901: 4900: 4888: 4883: 4882: 4881: 4876: 4871: 4866: 4856: 4851: 4846: 4841: 4840: 4839: 4834: 4824: 4823: 4822: 4817: 4812: 4807: 4797: 4792: 4791: 4790: 4785: 4780: 4770: 4769: 4768: 4763: 4758: 4753: 4748: 4743: 4733: 4728: 4723: 4718: 4717: 4716: 4711: 4706: 4701: 4691: 4686: 4684:Formation rule 4681: 4676: 4675: 4674: 4669: 4659: 4658: 4657: 4647: 4642: 4637: 4632: 4626: 4620: 4603:Formal systems 4599: 4598: 4595: 4594: 4592: 4591: 4586: 4581: 4576: 4571: 4566: 4561: 4556: 4551: 4546: 4545: 4544: 4539: 4528: 4526: 4522: 4521: 4519: 4518: 4517: 4516: 4506: 4501: 4500: 4499: 4492:Large cardinal 4489: 4484: 4479: 4474: 4469: 4455: 4454: 4453: 4448: 4443: 4428: 4426: 4416: 4415: 4413: 4412: 4411: 4410: 4405: 4400: 4390: 4385: 4380: 4375: 4370: 4365: 4360: 4355: 4350: 4345: 4340: 4335: 4329: 4327: 4320: 4319: 4317: 4316: 4315: 4314: 4309: 4304: 4299: 4294: 4289: 4281: 4280: 4279: 4274: 4264: 4259: 4257:Extensionality 4254: 4252:Ordinal number 4249: 4239: 4234: 4233: 4232: 4221: 4215: 4209: 4208: 4205: 4204: 4202: 4201: 4196: 4191: 4186: 4181: 4176: 4171: 4170: 4169: 4159: 4158: 4157: 4144: 4142: 4136: 4135: 4133: 4132: 4131: 4130: 4125: 4120: 4110: 4105: 4100: 4095: 4090: 4085: 4079: 4077: 4071: 4070: 4068: 4067: 4062: 4057: 4052: 4047: 4042: 4037: 4036: 4035: 4025: 4020: 4015: 4010: 4005: 4000: 3994: 3992: 3983: 3977: 3976: 3974: 3973: 3968: 3963: 3958: 3953: 3948: 3936:Cantor's  3934: 3929: 3924: 3914: 3912: 3899: 3898: 3896: 3895: 3890: 3885: 3880: 3875: 3870: 3865: 3860: 3855: 3850: 3845: 3840: 3835: 3834: 3833: 3822: 3820: 3816: 3815: 3810: 3808: 3807: 3800: 3793: 3785: 3779: 3778: 3764: 3759: 3745: 3744:External links 3742: 3741: 3740: 3734: 3719: 3713: 3700: 3694: 3677: 3665: 3659: 3641: 3623: 3617: 3587: 3584: 3581: 3580: 3554: 3525:(3): 283–312. 3500: 3490: 3464: 3442: 3431: 3396: 3385: 3370: 3359: 3346: 3333: 3326: 3302: 3295: 3271: 3258: 3239: 3228: 3219: 3210: 3180: 3169: 3144: 3118:(1): 253–77 , 3100: 3091:978-0030295584 3090: 3065: 3039: 3032: 3007: 2992: 2985: 2960: 2951: 2942:978-0470457931 2941: 2935:. p. 86. 2919: 2912: 2904:Academic Press 2887: 2868: 2851:Bill Casselman 2841: 2840: 2838: 2835: 2833: 2832: 2827: 2820: 2815: 2810: 2805: 2800: 2795: 2790: 2785: 2780: 2774: 2773: 2772: 2758: 2742: 2739: 2700:Main article: 2697: 2696:Ending a proof 2694: 2670: 2667: 2632: 2629: 2617:Bayes' theorem 2583: 2580: 2566:experiment or 2529:Main article: 2526: 2523: 2514: 2511: 2493: 2490: 2470:Main article: 2467: 2464: 2456: 2455: 2452: 2445: 2443: 2440: 2433: 2431: 2424: 2417: 2398: 2395: 2393: 2390: 2358:Main article: 2355: 2352: 2318: 2315: 2301:Main article: 2298: 2295: 2275:chaotic series 2259:Main article: 2256: 2253: 2252: 2251: 2240: 2235: 2231: 2210: 2207: 2202: 2196: 2190: 2184: 2178: 2172: 2165: 2159: 2135: 2130: 2127: 2104: 2097: 2091: 2088: 2065: 2058: 2033: 2028: 2025: 2022: 2019: 1996: 1989: 1959: 1952: 1923: 1895: 1891: 1859:Main article: 1856: 1853: 1833:Main article: 1830: 1827: 1788:Main article: 1785: 1782: 1756: 1752: 1748: 1743: 1739: 1716: 1712: 1708: 1703: 1700: 1697: 1693: 1672: 1650: 1646: 1642: 1637: 1633: 1610: 1606: 1602: 1597: 1593: 1570: 1566: 1562: 1559: 1556: 1551: 1547: 1527:Main article: 1523: 1520: 1507:Main article: 1504: 1501: 1497:counterexample 1477:Main article: 1474: 1471: 1452: 1439: 1438: 1424: 1326: 1323: 1318: 1313: 1279: 1276: 1271: 1266: 1242: 1210: 1183:Main article: 1180: 1177: 1176: 1175: 1163: 1138: 1134: 1111: 1107: 1086: 1083: 1080: 1077: 1072: 1068: 1047: 1027: 1003: 994:is even, then 981: 977: 956: 911:Contraposition 909:Main article: 906: 903: 899: 898: 889: − 1 879: 796: − 1 779: 735: − 1 712: − 1 704: 703: 681: 632: 533:Main article: 530: 527: 515: 514: 489: + 2 465: = 2 457: = 2 428:Main article: 425: 422: 420: 417: 330: 327: 273:mathematician 152: 149: 109:informal logic 96:Proofs employ 15: 13: 10: 9: 6: 4: 3: 2: 6029: 6028: 6017: 6014: 6012: 6009: 6007: 6004: 6002: 5999: 5997: 5994: 5993: 5991: 5976: 5973: 5970: 5966: 5963: 5961: 5958: 5956: 5946: 5945: 5942: 5932: 5931:Logic symbols 5929: 5927: 5924: 5922: 5919: 5917: 5914: 5912: 5909: 5908: 5906: 5902: 5896: 5893: 5891: 5888: 5886: 5883: 5882: 5880: 5878: 5874: 5871: 5867: 5861: 5858: 5856: 5853: 5851: 5848: 5846: 5843: 5841: 5838: 5836: 5833: 5831: 5828: 5826: 5823: 5821: 5818: 5816: 5813: 5811: 5810:Logical truth 5808: 5806: 5803: 5801: 5798: 5794: 5791: 5790: 5789: 5786: 5784: 5781: 5779: 5776: 5774: 5771: 5769: 5766: 5762: 5759: 5757: 5754: 5753: 5752: 5751:Contradiction 5749: 5747: 5744: 5742: 5739: 5737: 5734: 5732: 5729: 5728: 5726: 5722: 5712: 5709: 5707: 5704: 5702: 5699: 5697: 5696:Argumentation 5694: 5693: 5691: 5687: 5681: 5680:Philosophical 5678: 5676: 5675:Non-classical 5673: 5671: 5668: 5664: 5661: 5659: 5656: 5655: 5654: 5651: 5649: 5646: 5645: 5643: 5639: 5633: 5630: 5628: 5625: 5623: 5620: 5618: 5615: 5613: 5610: 5608: 5605: 5603: 5600: 5599: 5597: 5593: 5587: 5584: 5582: 5579: 5578: 5575: 5571: 5564: 5559: 5557: 5552: 5550: 5545: 5544: 5541: 5531: 5530: 5525: 5517: 5511: 5508: 5506: 5503: 5501: 5498: 5496: 5493: 5489: 5486: 5485: 5484: 5481: 5479: 5476: 5474: 5471: 5469: 5465: 5462: 5460: 5457: 5455: 5452: 5450: 5447: 5445: 5442: 5441: 5439: 5435: 5429: 5426: 5424: 5421: 5419: 5418:Recursive set 5416: 5414: 5411: 5409: 5406: 5404: 5401: 5399: 5396: 5392: 5389: 5387: 5384: 5382: 5379: 5377: 5374: 5372: 5369: 5368: 5367: 5364: 5362: 5359: 5357: 5354: 5352: 5349: 5347: 5344: 5342: 5339: 5338: 5336: 5334: 5330: 5324: 5321: 5319: 5316: 5314: 5311: 5309: 5306: 5304: 5301: 5299: 5296: 5294: 5291: 5287: 5284: 5282: 5279: 5277: 5274: 5273: 5272: 5269: 5267: 5264: 5262: 5259: 5257: 5254: 5252: 5249: 5247: 5244: 5240: 5237: 5236: 5235: 5232: 5228: 5227:of arithmetic 5225: 5224: 5223: 5220: 5216: 5213: 5211: 5208: 5206: 5203: 5201: 5198: 5196: 5193: 5192: 5191: 5188: 5184: 5181: 5179: 5176: 5175: 5174: 5171: 5170: 5168: 5166: 5162: 5156: 5153: 5151: 5148: 5146: 5143: 5141: 5138: 5135: 5134:from ZFC 5131: 5128: 5126: 5123: 5117: 5114: 5113: 5112: 5109: 5107: 5104: 5102: 5099: 5098: 5097: 5094: 5092: 5089: 5087: 5084: 5082: 5079: 5077: 5074: 5072: 5069: 5067: 5064: 5063: 5061: 5059: 5055: 5045: 5044: 5040: 5039: 5034: 5033:non-Euclidean 5031: 5027: 5024: 5022: 5019: 5017: 5016: 5012: 5011: 5009: 5006: 5005: 5003: 4999: 4995: 4992: 4990: 4987: 4986: 4985: 4981: 4977: 4974: 4973: 4972: 4968: 4964: 4961: 4959: 4956: 4954: 4951: 4949: 4946: 4944: 4941: 4939: 4936: 4935: 4933: 4929: 4928: 4926: 4921: 4915: 4910:Example  4907: 4899: 4894: 4893: 4892: 4889: 4887: 4884: 4880: 4877: 4875: 4872: 4870: 4867: 4865: 4862: 4861: 4860: 4857: 4855: 4852: 4850: 4847: 4845: 4842: 4838: 4835: 4833: 4830: 4829: 4828: 4825: 4821: 4818: 4816: 4813: 4811: 4808: 4806: 4803: 4802: 4801: 4798: 4796: 4793: 4789: 4786: 4784: 4781: 4779: 4776: 4775: 4774: 4771: 4767: 4764: 4762: 4759: 4757: 4754: 4752: 4749: 4747: 4744: 4742: 4739: 4738: 4737: 4734: 4732: 4729: 4727: 4724: 4722: 4719: 4715: 4712: 4710: 4707: 4705: 4702: 4700: 4697: 4696: 4695: 4692: 4690: 4687: 4685: 4682: 4680: 4677: 4673: 4670: 4668: 4667:by definition 4665: 4664: 4663: 4660: 4656: 4653: 4652: 4651: 4648: 4646: 4643: 4641: 4638: 4636: 4633: 4631: 4628: 4627: 4624: 4621: 4619: 4615: 4610: 4604: 4600: 4590: 4587: 4585: 4582: 4580: 4577: 4575: 4572: 4570: 4567: 4565: 4562: 4560: 4557: 4555: 4554:Kripke–Platek 4552: 4550: 4547: 4543: 4540: 4538: 4535: 4534: 4533: 4530: 4529: 4527: 4523: 4515: 4512: 4511: 4510: 4507: 4505: 4502: 4498: 4495: 4494: 4493: 4490: 4488: 4485: 4483: 4480: 4478: 4475: 4473: 4470: 4467: 4463: 4459: 4456: 4452: 4449: 4447: 4444: 4442: 4439: 4438: 4437: 4433: 4430: 4429: 4427: 4425: 4421: 4417: 4409: 4406: 4404: 4401: 4399: 4398:constructible 4396: 4395: 4394: 4391: 4389: 4386: 4384: 4381: 4379: 4376: 4374: 4371: 4369: 4366: 4364: 4361: 4359: 4356: 4354: 4351: 4349: 4346: 4344: 4341: 4339: 4336: 4334: 4331: 4330: 4328: 4326: 4321: 4313: 4310: 4308: 4305: 4303: 4300: 4298: 4295: 4293: 4290: 4288: 4285: 4284: 4282: 4278: 4275: 4273: 4270: 4269: 4268: 4265: 4263: 4260: 4258: 4255: 4253: 4250: 4248: 4244: 4240: 4238: 4235: 4231: 4228: 4227: 4226: 4223: 4222: 4219: 4216: 4214: 4210: 4200: 4197: 4195: 4192: 4190: 4187: 4185: 4182: 4180: 4177: 4175: 4172: 4168: 4165: 4164: 4163: 4160: 4156: 4151: 4150: 4149: 4146: 4145: 4143: 4141: 4137: 4129: 4126: 4124: 4121: 4119: 4116: 4115: 4114: 4111: 4109: 4106: 4104: 4101: 4099: 4096: 4094: 4091: 4089: 4086: 4084: 4081: 4080: 4078: 4076: 4075:Propositional 4072: 4066: 4063: 4061: 4058: 4056: 4053: 4051: 4048: 4046: 4043: 4041: 4038: 4034: 4031: 4030: 4029: 4026: 4024: 4021: 4019: 4016: 4014: 4011: 4009: 4006: 4004: 4003:Logical truth 4001: 3999: 3996: 3995: 3993: 3991: 3987: 3984: 3982: 3978: 3972: 3969: 3967: 3964: 3962: 3959: 3957: 3954: 3952: 3949: 3947: 3943: 3939: 3935: 3933: 3930: 3928: 3925: 3923: 3919: 3916: 3915: 3913: 3911: 3905: 3900: 3894: 3891: 3889: 3886: 3884: 3881: 3879: 3876: 3874: 3871: 3869: 3866: 3864: 3861: 3859: 3856: 3854: 3851: 3849: 3846: 3844: 3841: 3839: 3836: 3832: 3829: 3828: 3827: 3824: 3823: 3821: 3817: 3813: 3806: 3801: 3799: 3794: 3792: 3787: 3786: 3783: 3777: 3773: 3769: 3765: 3763: 3760: 3757: 3752: 3748: 3747: 3743: 3737: 3731: 3727: 3726: 3725:Book of Proof 3720: 3716: 3710: 3706: 3701: 3697: 3691: 3687: 3683: 3678: 3674: 3670: 3666: 3662: 3656: 3653:, Kew Books, 3652: 3651: 3646: 3642: 3637: 3633: 3629: 3624: 3620: 3618:9780691080055 3614: 3609: 3604: 3600: 3599: 3594: 3590: 3589: 3585: 3569: 3565: 3558: 3555: 3550: 3546: 3541: 3540:2027.42/42653 3536: 3532: 3528: 3524: 3520: 3519: 3511: 3504: 3501: 3497: 3493: 3487: 3483: 3478: 3477: 3468: 3465: 3461: 3456: 3452: 3446: 3443: 3439: 3434: 3428: 3424: 3420: 3419: 3414: 3413:Wright, David 3410: 3406: 3400: 3397: 3394: 3389: 3386: 3383: 3380: 3374: 3371: 3368: 3363: 3360: 3356: 3350: 3347: 3343: 3337: 3334: 3329: 3323: 3319: 3315: 3314: 3306: 3303: 3298: 3292: 3288: 3284: 3283: 3275: 3272: 3268: 3262: 3259: 3255: 3251: 3248: 3243: 3240: 3237: 3232: 3229: 3223: 3220: 3214: 3211: 3198: 3191: 3184: 3181: 3177: 3172: 3166: 3162: 3158: 3154: 3148: 3145: 3141: 3137: 3133: 3129: 3125: 3121: 3117: 3113: 3112: 3104: 3101: 3097: 3093: 3087: 3083: 3079: 3075: 3069: 3066: 3054: 3050: 3043: 3040: 3035: 3029: 3026:. p. 3. 3025: 3021: 3017: 3011: 3008: 3004: 2999: 2997: 2993: 2988: 2982: 2978: 2974: 2970: 2964: 2961: 2955: 2952: 2948: 2944: 2938: 2934: 2930: 2923: 2920: 2915: 2909: 2906:. p. 3. 2905: 2901: 2897: 2891: 2888: 2884: 2879: 2872: 2869: 2861:September 26, 2856: 2852: 2846: 2843: 2836: 2831: 2828: 2826: 2825: 2821: 2819: 2816: 2814: 2811: 2809: 2806: 2804: 2801: 2799: 2796: 2794: 2791: 2789: 2786: 2784: 2783:Invalid proof 2781: 2779: 2776: 2775: 2770: 2764: 2759: 2756: 2745: 2740: 2738: 2732: 2729: 2725: 2721: 2717: 2713: 2709: 2703: 2695: 2693: 2691: 2690: 2685: 2681: 2676: 2668: 2666: 2664: 2660: 2656: 2652: 2648: 2642: 2638: 2630: 2628: 2626: 2622: 2618: 2613: 2611: 2607: 2603: 2599: 2596:Proofs using 2593: 2589: 2581: 2579: 2577: 2576:scatter plots 2573: 2569: 2565: 2561: 2560: 2554: 2550: 2546: 2542: 2538: 2537:data analysis 2532: 2524: 2522: 2520: 2512: 2510: 2507: 2498: 2491: 2489: 2487: 2483: 2479: 2478:number theory 2473: 2465: 2463: 2461: 2449: 2444: 2437: 2432: 2428: 2421: 2416: 2414: 2412: 2408: 2404: 2396: 2391: 2389: 2387: 2383: 2379: 2375: 2371: 2367: 2361: 2353: 2351: 2349: 2345: 2343: 2339: 2334: 2332: 2328: 2324: 2316: 2314: 2311: 2308:proof of the 2304: 2296: 2294: 2292: 2288: 2284: 2280: 2276: 2272: 2268: 2262: 2254: 2238: 2233: 2229: 2208: 2205: 2200: 2194: 2188: 2182: 2176: 2170: 2163: 2157: 2133: 2128: 2125: 2102: 2095: 2089: 2086: 2063: 2056: 2031: 2026: 2023: 2020: 2017: 1994: 1987: 1976: 1975: 1974: 1957: 1950: 1939: 1921: 1911: 1893: 1889: 1880: 1876: 1873: 1868: 1862: 1854: 1852: 1850: 1846: 1842: 1836: 1828: 1826: 1824: 1820: 1816: 1812: 1807: 1803: 1801: 1797: 1791: 1783: 1781: 1779: 1775: 1770: 1754: 1750: 1741: 1737: 1714: 1710: 1701: 1698: 1695: 1691: 1670: 1648: 1644: 1635: 1631: 1608: 1604: 1595: 1591: 1568: 1564: 1560: 1557: 1554: 1549: 1545: 1535: 1532: 1531: 1530: 1521: 1519: 1517: 1510: 1502: 1500: 1498: 1494: 1490: 1486: 1480: 1472: 1470: 1468: 1450: 1422: 1412: 1408: 1404: 1400: 1396: 1392: 1388: 1384: 1380: 1376: 1372: 1368: 1364: 1360: 1356: 1352: 1348: 1344: 1340: 1324: 1321: 1316: 1311: 1303: 1299: 1295: 1277: 1274: 1269: 1264: 1240: 1231:Suppose that 1230: 1229: 1228: 1226: 1208: 1198: 1194: 1193: 1186: 1178: 1161: 1153: 1136: 1132: 1109: 1105: 1097:is odd. Thus 1084: 1081: 1078: 1075: 1070: 1066: 1045: 1025: 1017: 1016: 1015: 1001: 979: 975: 954: 945: 943: 939: 935: 932: 928: 924: 920: 917: 912: 904: 902: 895: 888: 883: 880: 875: 871: 864: 860: 853: 849: 842: 834: 830: 826: 814: 806: 802: 795: 788: 783: 780: 775: 756: 748: 743: 740: 739: 738: 734: 726: 722: 717: 711: 702: 699: 692: 688: 682: 677: 673: 666: 662: 655: 651: 644: 640: 636: 633: 628: 621: 617: 610: 606: 603: 602: 601: 598: 594:belonging to 592: 585: 581: 574: 569: 564: 562: 558: 554: 550: 546: 542: 536: 528: 526: 524: 520: 512: 508: 504: 501:). Therefore 500: 496: 492: 488: 484: 481: +  480: 476: 472: 468: 464: 460: 456: 452: 448: 444: 443: 442: 440: 437: 431: 423: 418: 416: 414: 413: 408: 404: 399: 397: 393: 389: 385: 381: 377: 373: 367: 365: 361: 356: 352: 348: 344: 339: 336: 328: 326: 324: 320: 316: 312: 307: 305: 301: 297: 293: 289: 285: 281: 276: 272: 268: 263: 261: 260:prime numbers 257: 253: 249: 248:number theory 245: 241: 237: 236: 231: 227: 223: 219: 215: 210: 208: 204: 200: 196: 192: 188: 184: 178: 176: 172: 168: 164: 158: 150: 148: 146: 142: 138: 134: 130: 126: 122: 118: 114: 113:formal proofs 110: 107: 103: 99: 94: 92: 88: 84: 80: 76: 72: 68: 64: 60: 56: 52: 49: 45: 37: 36: 31: 27: 23: 19: 6011:Proof theory 5850:Substitution 5670:Mathematical 5595:Major fields 5520: 5318:Ultraproduct 5165:Model theory 5130:Independence 5066:Formal proof 5058:Proof theory 5041: 5014: 4971:real numbers 4943:second-order 4854:Substitution 4731:Metalanguage 4672:conservative 4645:Axiom schema 4589:Constructive 4559:Morse–Kelley 4525:Set theories 4504:Aleph number 4497:inaccessible 4403:Grothendieck 4287:intersection 4174:Higher-order 4162:Second-order 4108:Truth tables 4065:Venn diagram 3848:Formal proof 3724: 3704: 3681: 3672: 3669:Gold, Bonnie 3649: 3645:Franklin, J. 3635: 3631: 3597: 3571:. Retrieved 3567: 3557: 3522: 3516: 3503: 3495: 3475: 3467: 3458: 3455:the original 3445: 3436: 3416: 3399: 3388: 3378: 3373: 3362: 3354: 3349: 3341: 3336: 3317: 3312: 3305: 3286: 3281: 3274: 3261: 3242: 3231: 3222: 3213: 3201:. Retrieved 3199:. p. 12 3196: 3183: 3160: 3147: 3115: 3109: 3103: 3095: 3077: 3068: 3056:. Retrieved 3052: 3042: 3019: 3010: 2972: 2969:Hacking, Ian 2963: 2954: 2946: 2928: 2922: 2899: 2890: 2881: 2877: 2871: 2859:. Retrieved 2845: 2822: 2719: 2711: 2707: 2705: 2688: 2672: 2644: 2637:Psychologism 2614: 2595: 2557: 2552: 2548: 2534: 2516: 2503: 2475: 2457: 2400: 2397:Visual proof 2363: 2346: 2335: 2320: 2306: 2271:cryptography 2264: 1878: 1874: 1864: 1843:between two 1838: 1808: 1804: 1793: 1774:transitivity 1771: 1536: 1533: 1526: 1525: 1512: 1482: 1440: 1410: 1406: 1402: 1398: 1394: 1390: 1386: 1382: 1378: 1374: 1370: 1366: 1362: 1358: 1350: 1346: 1342: 1338: 1297: 1293: 1190: 1188: 1151: 946: 941: 937: 926: 922: 914: 900: 893: 886: 881: 873: 869: 862: 858: 851: 847: 840: 832: 828: 824: 812: 804: 800: 793: 786: 781: 773: 754: 746: 741: 732: 724: 720: 709: 705: 697: 690: 686: 683: 675: 671: 664: 660: 653: 649: 642: 638: 634: 626: 624:is true for 619: 615: 608: 604: 596: 590: 583: 579: 572: 565: 538: 516: 506: 502: 498: 494: 490: 486: 482: 478: 474: 470: 466: 462: 458: 454: 450: 446: 433: 430:Direct proof 424:Direct proof 410: 400: 368: 360:proof theory 347:formal proof 340: 332: 311:proof theory 308: 291: 264: 246:also covers 243: 234: 211: 179: 174: 170: 166: 162: 160: 121:proof theory 95: 86: 43: 41: 33: 18: 5965:WikiProject 5835:Proposition 5830:Probability 5783:Description 5724:Foundations 5428:Type theory 5376:undecidable 5308:Truth value 5195:equivalence 4874:non-logical 4487:Enumeration 4477:Isomorphism 4424:cardinality 4408:Von Neumann 4373:Ultrafilter 4338:Uncountable 4272:equivalence 4189:Quantifiers 4179:Fixed-point 4148:First-order 4028:Consistency 4013:Proposition 3990:Traditional 3961:Lindström's 3951:Compactness 3893:Type theory 3838:Cardinality 3776:Wikiversity 3573:October 15, 3379:statistical 3203:October 20, 3082:Brooks/Cole 3058:October 20, 2731:Paul Halmos 2714:, which is 2602:probability 2553:assumptions 2545:probability 729:represent " 509:has 2 as a 5990:Categories 5895:Set theory 5793:Linguistic 5788:Entailment 5778:Definition 5746:Consequent 5741:Antecedent 5239:elementary 4932:arithmetic 4800:Quantifier 4778:functional 4650:Expression 4368:Transitive 4312:identities 4297:complement 4230:hereditary 4213:Set theory 3482:Icon Books 3357:94:165–86. 3344:79:252–63. 2837:References 2692:argument. 1881:such that 600:such that 553:infinitely 493: = 2( 407:Paul Erdős 294:(1000) by 275:Al-Hashimi 256:irrational 203:Theaetetus 155:See also: 91:conjecture 26:P. Oxy. 29 5926:Fallacies 5921:Paradoxes 5911:Logicians 5845:Statement 5840:Reference 5805:Induction 5768:Deduction 5731:Abduction 5701:Metalogic 5648:Classical 5612:Inference 5510:Supertask 5413:Recursion 5371:decidable 5205:saturated 5183:of models 5106:deductive 5101:axiomatic 5021:Hilbert's 5008:Euclidean 4989:canonical 4912:axiomatic 4844:Signature 4773:Predicate 4662:Extension 4584:Ackermann 4509:Operation 4388:Universal 4378:Recursive 4353:Singleton 4348:Inhabited 4333:Countable 4323:Types of 4307:power set 4277:partition 4194:Predicate 4140:Predicate 4055:Syllogism 4045:Soundness 4018:Inference 4008:Tautology 3910:paradoxes 3593:Pólya, G. 3176:p. 3 3140:121416910 2971:(1984) . 2898:(2005) . 2883:obtained. 2724:tombstone 2684:Descartes 2680:certainty 2606:certainty 1841:bijection 1751:φ 1747:⇒ 1738:φ 1711:φ 1707:⇒ 1699:− 1692:φ 1671:… 1645:φ 1641:⇒ 1632:φ 1605:φ 1601:⇒ 1592:φ 1565:φ 1558:… 1546:φ 1082:⋅ 1014:is even: 737:is odd": 541:deduction 485: = 2 380:synthetic 296:Al-Karaji 292:Al-Fakhri 207:Aristotle 175:probieren 111:. Purely 79:empirical 71:inference 59:logically 48:deductive 5960:Category 5860:Validity 5761:Antinomy 5689:Theories 5653:Informal 5495:Logicism 5488:timeline 5464:Concrete 5323:Validity 5293:T-schema 5286:Kripke's 5281:Tarski's 5276:semantic 5266:Strength 5215:submodel 5210:spectrum 5178:function 5026:Tarski's 5015:Elements 5002:geometry 4958:Robinson 4879:variable 4864:function 4837:spectrum 4827:Sentence 4783:variable 4726:Language 4679:Relation 4640:Automata 4630:Alphabet 4614:language 4468:-jection 4446:codomain 4432:Function 4393:Universe 4363:Infinite 4267:Relation 4050:Validity 4040:Argument 3938:theorem, 3638:: 373–88 3595:(1954), 3549:23084607 3415:(2002). 3250:Archived 2741:See also 2708:"Q.E.D." 2625:evidence 2411:triangle 1467:fraction 1365:, where 1304:. 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Let 549:implies 519:closure 309:Modern 199:Eudoxus 171:provare 163:probare 5877:topics 5663:Reason 5641:Logics 5632:Syntax 5200:finite 4963:Skolem 4916:  4891:Theory 4859:Symbol 4849:String 4832:atomic 4709:ground 4704:closed 4699:atomic 4655:ground 4618:syntax 4514:binary 4441:domain 4358:Finite 4123:finite 3981:Logics 3940:  3888:Theory 3772:course 3768:lesson 3732:  3711:  3692:  3675:. 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A 321:and 286:for 224:and 5711:Set 5000:of 4982:of 4930:of 4462:Sur 4436:Map 4243:Ur- 4225:Set 3603:hdl 3535:hdl 3527:doi 3128:doi 3116:500 2570:in 2281:or 1385:= 2 1361:= 2 944:". 876:+1) 854:+1) 776:(1) 749:= 1 742:(i) 716:odd 678:+1) 645:+1) 629:= 1 611:(1) 605:(i) 378:or 254:is 87:all 32:'s 5992:: 5386:NP 5010:: 5004:: 4934:: 4611:), 4466:Bi 4458:In 3766:A 3688:, 3684:, 3636:45 3634:, 3630:, 3611:, 3566:. 3543:. 3533:. 3523:49 3521:. 3515:. 3494:. 3484:. 3480:. 3435:. 3425:. 3421:. 3411:; 3407:; 3195:. 3134:, 3126:, 3114:, 3094:. 3051:. 2995:^ 2979:. 2975:. 2945:. 2931:. 2880:. 2853:. 2737:. 2686:' 2665:. 2649:, 2612:. 2413:. 2344:. 2333:. 2273:, 1802:. 1780:. 1769:. 1683:, 1663:, 1623:, 1341:= 1227:: 1152:is 839:2( 823:(2 811:(2 751:, 563:. 525:. 382:. 325:. 306:. 262:. 147:. 131:, 42:A 5971:) 5562:e 5555:t 5548:v 5466:/ 5381:P 5136:) 4922:) 4918:( 4815:∀ 4810:! 4805:∃ 4766:= 4761:↔ 4756:→ 4751:∧ 4746:∨ 4741:¬ 4464:/ 4460:/ 4434:/ 4245:) 4241:( 4128:∞ 4118:3 3906:) 3804:e 3797:t 3790:v 3739:. 3718:. 3699:. 3664:. 3640:. 3622:. 3605:: 3577:. 3551:. 3537:: 3529:: 3330:. 3299:. 3269:. 3207:. 3130:: 3122:: 3062:. 3036:. 2989:. 2916:. 2865:. 2239:. 2234:b 2230:a 2209:2 2206:= 2201:2 2195:2 2189:= 2183:2 2177:) 2171:2 2164:2 2158:( 2134:2 2129:= 2126:b 2103:2 2096:2 2090:= 2087:a 2064:2 2057:2 2032:2 2027:= 2024:b 2021:= 2018:a 1995:2 1988:2 1958:2 1951:2 1922:2 1894:b 1890:a 1879:b 1875:a 1755:1 1742:n 1715:n 1702:1 1696:n 1649:3 1636:2 1609:2 1596:1 1569:n 1561:, 1555:, 1550:1 1451:2 1423:2 1411:b 1407:a 1403:b 1399:a 1395:b 1391:b 1387:c 1383:b 1379:c 1375:c 1371:b 1367:c 1363:c 1359:a 1351:a 1347:a 1343:a 1339:b 1325:a 1322:= 1317:2 1312:b 1298:b 1294:a 1278:b 1275:a 1270:= 1265:2 1241:2 1209:2 1162:x 1137:2 1133:x 1110:2 1106:x 1085:x 1079:x 1076:= 1071:2 1067:x 1046:x 1026:x 1002:x 980:2 976:x 955:x 927:q 923:p 897:. 894:n 887:n 885:2 878:. 874:n 872:( 870:P 865:) 863:n 861:( 859:P 852:n 850:( 848:P 841:n 833:n 829:n 825:n 819:2 813:n 807:) 805:n 803:( 801:P 794:n 792:2 787:n 774:P 769:2 765:1 761:1 755:n 753:2 747:n 733:n 731:2 727:) 725:n 723:( 721:P 710:n 708:2 701:. 698:n 693:) 691:n 689:( 687:P 676:n 674:( 672:P 667:) 665:n 663:( 661:P 656:) 654:n 652:( 650:P 643:n 641:( 639:P 631:. 627:n 622:) 620:n 618:( 616:P 609:P 597:N 591:n 586:) 584:n 582:( 580:P 573:N 507:y 505:+ 503:x 499:b 497:+ 495:a 491:b 487:a 483:y 479:x 475:b 471:a 467:b 463:y 459:a 455:x 451:y 447:x

Index


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
geometry

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