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Three-valued logic

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390:; the addition of a third value in ternary logic leads to a total of 3 = 27 distinct operators on a single input value. (This may be made clear by considering all possible truth tables for an arbitrary unary operator. Given 2 possible values TF of the single Boolean input, there are four different patterns of output TT, TF, FT, FF resulting from the following unary operators acting on each value: always T, Identity, NOT, always F. Given three possible values of a ternary variable, each times three possible results of a unary operation, there are 27 different output patterns: TTT, TTU, TTF, TUT, TUU, TUF, TFT, TFU, TFF, UTT, UTU, UTF, UUT, UUU, UUF, UFT, UFU, UFF, FTT, FTU, FTF, FUT, FUU, FUF, FFT, FFU, and FFF.) Similarly, where Boolean logic has 2 = 16 distinct binary operators (operators with 2 inputs) possible, ternary logic has 3 = 19,683 such operators. Where the nontrival Boolean operators can be named ( 2996:
each on a subset of the natural numbers (as occurs e.g. after completing the definitions of any two partial recursive predicates classically). Let t, f, u mean 'decidable by the algorithms (i.e. by use of only such information about Q(x) and R(x) as can be obtained by the algorithms) to be true', 'decidable by the algorithms to be false', 'undecidable by the algorithms whether true or false'. (iv) Assume a fixed state of knowledge about Q(x) and R(x) (as occurs e.g. after pursuing algorithms for each of them up to a given stage). Let t, f, u mean 'known to be true', 'known to be false', 'unknown whether true or false'.
219:. He never published it. In fact, he did not even number the three pages of notes where he defined his three-valued operators. Peirce soundly rejected the idea all propositions must be either true or false; boundary-propositions, he writes, are "at the limit between P and not P." However, as confident as he was that "Triadic Logic is universally true," he also jotted down that "All this is mighty close to nonsense." Only in 1966, when Max Fisch and Atwell Turquette began publishing what they rediscovered in his unpublished manuscripts, did Peirce's triadic ideas become widely known. 245:
observational data that a statement as to the position of a motor car can never be falsified or verified, then there may be some point to not regarding the statement as true or false, but regarding it as "middle." It is only because, in macrocosmic experience, everything that we regard as an empirically meaningful statement seems to be at least potentially verifiable or falsifiable that we prefer the convention according to which we say that every such statement is either true or false, but in many cases we don't know which.
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However, it is not the case that 'middle' means "neither verified nor falsified at the present time." As we have seen, 'verified' and 'falsified' are epistemic predicates--that is to say, they are relative to the evidence at a particular time--whereas 'middle,' like 'true' and 'false' is not relative
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truth value for Kleene logic is True.) However, the lack of valid formulas does not mean that it lacks valid arguments and/or inference rules. An argument is semantically valid in Kleene logic if, whenever (for any interpretation/model) all of its premises are True, the conclusion must also be True.
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The strong 3-valued logic can be applied to completely defined predicates Q(x) and R(x), from which composite predicates are formed using ̅, V, &, ->, ≡ in the usual 2-valued meanings, thus, (iii) Suppose that there are fixed algorithms which decide the truth or falsity of Q(x) and of R(x),
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But there is a second possible way to conceive of many-valued logics: that while a proposition, in itself, can have only two values, true or false, that is to say two responses, yes or no, it may happen that a given individual does not know the response, at least at a given moment; therefore, for
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state can be thought of as neither true nor false in Kleene logic, or thought of as both true and false in Priest logic. The difference lies in the definition of tautologies. Where Kleene logic's only designated truth value is T, Priest logic's designated truth values are both T and U. In Kleene
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For example, if we have verified (by using a speedometer) that the velocity of a motor car is such and such, it might be impossible in such a world to verify or falsify certain statements concerning its position at that moment. If we know by reference to a physical law together with certain
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or inequality), with six trivial operators considering 0 or 1 inputs only, it is unreasonable to attempt to name all but a small fraction of the possible ternary operators. Just as in bivalent logic, where not all operators are given names and subsets of
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Broadly speaking, the primary motivation for research of three valued logic is to represent the truth value of a statement that cannot be represented as true or false. Łukasiewicz initially developed three valued logic for the
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Kleene logic has no tautologies (valid formulas) because whenever all of the atomic components of a well-formed formula are assigned the value Unknown, the formula itself must also have the value Unknown. (And the only
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is credited with first introducing additional logical truth degrees in his 1921 theory of elementary propositions. The conceptual form and basic ideas of three-valued logic were initially published by
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the individual there is a third attitude possible toward a proposition. This third attitude does not correspond to a distinct third value of yes or of no, but simply to a doubt between yes or no
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where the third truth value NF (not false) has the semantics of a proposition that can be intuitionistically proven to not be false, but does not have an intuitionistic proof of correctness.
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using a three-valued logic, "it is possible that..." L is read "it is true that..." or "it is necessary that..." Finally I is read "it is unknown that..." or "it is contingent that..."
1106: 2355:, or by explicit truth tables for its operations. In particular, conjunction and disjunction are the same as for Kleene's and Łukasiewicz's logic, while the negation is different. 1391:
The Łukasiewicz Ł3 has the same tables for AND, OR, and NOT as the Kleene logic given above, but differs in its definition of implication in that "unknown implies unknown" is
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truth values instead of one; these are: True and Both (the analogue of Unknown), so that LP does have tautologies but it has fewer valid inference rules).
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RM3 is a non-cartesian symmetric monoidal closed category; the product, which is left-adjoint to the implication, lacks valid projections, and has
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in the lattice of intermediate logics. In this sense it may be viewed as the "second strongest" intermediate logic after classical logic.
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Cobreros, Pablo; Égré, Paul; Ripley, David; Rooij, Robert van (2 January 2014). "Foreword: Three-valued logics and their applications".
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Mundici, D. The C*-Algebras of Three-Valued Logic. Logic Colloquium ’88, Proceedings of the Colloquium held in Padova 61–77 (1989).
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at any moment in time is not available. However, certain logical operations can yield an unambiguous result, even if they involve an
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are tautologies in Ł3 and also in classical logic. Not all tautologies of classical logic lift to Ł3 "as is". For example, the
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As with bivalent logic, truth values in ternary logic may be represented numerically using various representations of the
229: 68: 4329: 5183: 5009: 4695: 3928: 3271: 4334: 4666: 4405: 3663: 3564: 3432: 3170:. Synthesis lectures on digital circuits and systems. Vol. 12. Morgan & Claypool Publishers. pp. 41–42. 2503: 1967: 5061: 5056: 2662:"Peirce's Deductive Logic > Peirce's Three-Valued Logic (Stanford Encyclopedia of Philosophy/Summer 2020 Edition)" 75: 5329: 5324: 4990: 4580: 3974: 3942: 3633: 3325: 308:, only the least-significant non-zero digit can have a value of 2, and the remaining digits have a value of 0 or 1; 236:
used a third value to represent when "a given individual does not know the response, at least at a given moment."
3707: 2578: 35: 5280: 5229: 5126: 4624: 4585: 4062: 2523: 305: 196: 5121: 3736: 1190:{\displaystyle A\rightarrow B\ {\overset {\underset {\mathrm {def} }{}}{=}}\ {\mbox{OR}}(\ {\mbox{NOT}}(A),\ B)} 5051: 4590: 4442: 4425: 4148: 3628: 1900: 57: 277:, each digit has one of 3 values: −1, 0, or +1; these values may also be simplified to −, 0, +, respectively; 4953: 4930: 4891: 4777: 4718: 4364: 4284: 4128: 4072: 3685: 3330: 3026: 5243: 4970: 4948: 4915: 4808: 4654: 4639: 4612: 4563: 4447: 4382: 4207: 4173: 4168: 4042: 3873: 3850: 2539: 1942: 1886: 288: 266: 212: 166: 2473:
field content. SQL uses a common fragment of the Kleene K3 logic, restricted to AND, OR, and NOT tables.
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M is read as "it is not false that..." or in the (unsuccessful) Tarski–Łukasiewicz attempt to axiomatize
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In fact, using Łukasiewicz's implication and negation, the other usual connectives may be derived as:
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have been introduced more recently, motivated by circuit problems rather than philosophical issues:
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It is also possible to derive a few other useful unary operators (first derived by Tarski in 1921):
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Rybaříková, Zuzana (1 May 2021). "Łukasiewicz, determinism, and the four-valued system of logic".
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An Introduction to Many-Valued and Fuzzy Logic: Semantics, Algebras, and Derivation Systems
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Handbook of the History of Logic Volume 8. The Many Valued and Nonmonotonic Turn in Logic
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operators are used, there may be functionally complete sets of ternary-valued operators.
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is True, meaning that only a proposition having this value everywhere is considered a
5318: 5193: 4871: 4378: 4163: 4153: 4123: 4108: 3778: 2993:. North-Holland Publishing Co., Amsterdam, and P. Noordhoff, Groningen. p. 336. 450: 383: 237: 170: 5093: 4940: 4841: 4833: 4713: 4661: 4570: 4506: 4489: 4420: 4279: 4138: 3840: 3623: 3396: 3302: 3008: 395: 1098:, then A AND B AND C... = MIN(A, B, C ...) and A OR B OR C ... = MAX(A, B, C...). 2808: 5203: 5083: 4262: 4252: 4199: 3883: 3803: 3788: 3668: 3613: 3414: 3340: 2740:"Logic : autograph manuscript notebook, November 12, 1865-November 1, 1909" 2710:"Logic : autograph manuscript notebook, November 12, 1865-November 1, 1909" 1851: 1055:
as well. In this example, because either bivalent state could be underlying the
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using the truth values {false, unknown, true}, and extends conventional Boolean
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de Finetti, Bruno (1 January 1995). "The logic of probability (translated)".
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defined above, it is possible to state tautologies that are their analogues:
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Triadic Logic is universally true. But Dyadic Logic is not aboslutely false
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to represent the truth value of statements about the undetermined future.
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which, by adjointness, is equivalent to the projection from the product:
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This logic is also known as a weak form of Kleene's three-valued logic.
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A defining characteristic of RM3 is the lack of the axiom of Weakening:
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It may be defined either by appending one of the two equivalent axioms
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Paraconsistent logic § An ideal three-valued paraconsistent logic
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Heyting (1930). "Die formalen Regeln der intuitionistischen Logik".
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hollisarchives.lib.harvard.edu/repositories/24/digital_objects/63983
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hollisarchives.lib.harvard.edu/repositories/24/digital_objects/63983
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The truth table for the material implication of R-mingle 3 (RM3) is
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implements ternary logic as a means of handling comparisons with
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which differs from that for Łukasiewicz logic (described below).
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used it to represent values that cannot physically be decided:
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Many-valued logic § Bochvar's internal three-valued logic
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that are "undecidable by algorithms whether true or false"
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not(a) = (a + 1) mod (n), where (n) is the value of a logic
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Material implication for Łukasiewicz logic truth table is
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Material implication for Kleene logic can be defined as:
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Putnam, Hilary (1 October 1957). "Three-valued logic".
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as the monoid identity. This logic is equivalent to an
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are not tautologies in Ł3. However, using the operator
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The Penguin Dictionary of Mathematics. Fourth Edition
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state, and either state also yields the same result,
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in an axiomatic algebraic form, and also extended to
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This article mainly illustrates a system of ternary
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Multiple valued logic: concepts and representations
49:. Unsourced material may be challenged and removed. 3166:Miller, D. Michael; Thornton, Mitchell A. (2008). 1189: 2207: 1836: 1791: 1746: 707: 634: 561: 494: 3192:Multiple-Valued Logic Synthesis and Optimization 2256: 2248: 2191: 2017: 2009: 1820: 1775: 1730: 1440: 1432: 1235: 1227: 947: 874: 801: 676: 671: 603: 598: 530: 525: 478: 2242: 2134:Many-valued logic § Gödel logics Gk and G∞ 2003: 1426: 1221: 1003:logic, the knowledge of whether any particular 665: 592: 519: 242: 3253:. University of California Press. Dover 1998: 301:(trinary digit) having a value of: 0, 1, or 2; 3572: 3279: 8: 3251:Philosophic Foundations of Quantum Mechanics 3050:, the Scientific Research Society: 490–494. 2824:"Three-Valued Logic and Future Contingents" 4398: 3993: 3761: 3579: 3565: 3557: 3286: 3272: 3264: 2790: 2788: 2786: 269:. A few of the more common examples are: 2645: 2627: 2617: 1159: 1146: 1129: 1122: 1108: 109:Learn how and when to remove this message 3198:, Kluwer Academic Publishers, pp. 89-114 2224: 2173: 1985: 1802: 1757: 1712: 1485: 1408: 1280: 1203: 922: 849: 776: 735: 651: 578: 505: 464: 169:logics (such as classical sentential or 3194:, in Hassoun S. and Sasao T., editors, 2797:Journal of Applied Non-Classical Logics 2570: 449:'s "strong logic of indeterminacy" and 16:System including an indeterminate value 3137:" in Dov M. Gabbay, John Woods (eds.) 3013:The Art of Computer Programming Vol. 2 2746:. Houghton Library, Harvard University 2716:. Houghton Library, Harvard University 1706:They have the following truth tables: 2863:"The Problem of Future Contingencies" 2234: 2118:which also obeys the contrapositive. 1995: 1495: 1418: 1290: 1213: 928: 855: 782: 657: 584: 511: 7: 3135:Many-valued Logic and its Philosophy 1545: 1340: 950: 877: 804: 360:, ternary values are represented by 47:adding citations to reliable sources 2828:The Philosophical Quarterly (1950-) 2168:(F, false; NF, not false; T, true) 195:. These were then re-formulated by 2142:, also referred as Smetanov logic 1136: 1133: 1130: 730:(−1, false; 0, unknown; +1, true) 14: 2697:from the original on Dec 6, 2023. 2589:from the original on May 3, 2023. 445:showing the logic operations for 153:systems in which there are three 5298: 3196:Logic Synthesis and Verification 2771:www.digitalpeirce.fee.unicamp.br 2738:Peirce, Charles S. (1839–1914). 2708:Peirce, Charles S. (1839–1914). 2579:"Trilean (Stanford JavaNLP API)" 2483: 2382: 2154:in 1930 as a model for studying 1968:extended contradiction principle 1397:Handbook of the History of Logic 459:(F, false; U, unknown; T, true) 437:Kleene algebra (with involution) 253:used a third value to represent 23: 3065:from the original on 2019-10-30 2991:Introduction to metamathematics 2606:American Journal of Mathematics 2220: 2164: 1981: 1708: 1404: 1199: 924:MIN(MAX(A, B), NEG(MIN(A, B))) 726: 455: 282:redundant binary representation 34:needs additional citations for 3217:. Cambridge University Press. 2629:2027/uiuo.ark:/13960/t9j450f7q 1184: 1172: 1166: 1153: 1113: 1019:operand. For example, because 1: 5259:History of mathematical logic 3245:10.1016/s0049-237x(08)70262-3 2989:Kleene, Stephen Cole (1952). 2499:Binary logic (disambiguation) 2222: 2171: 2138:The logic of here and there ( 1983: 1710: 1406: 1201: 733: 462: 230:problem of future contingents 5184:Primitive recursive function 3123:"Beyond Propositional Logic" 2809:10.1080/11663081.2014.909631 2465:The database query language 2116:"ideal" paraconsistent logic 1063:results in all three cases. 3433:Ontology (computer science) 2504:Boolean algebra (structure) 998:In these truth tables, the 5346: 4248:Schröder–Bernstein theorem 3975:Monadic predicate calculus 3634:Foundations of mathematics 3326:Intuitionistic type theory 3249:Reichenbach, Hans (1944). 3029:(November–December 2001). 2458: 2419:not(a) = (a + 1) mod 3, or 2369: 2131: 2125: 1384: 1007:state secretly represents 434: 5294: 5281:Philosophy of mathematics 5230:Automated theorem proving 4401: 4355:Von Neumann–Bernays–Gödel 3996: 3211:Bergmann, Merrie (2008). 2524:Homogeneity (linguistics) 2445:Dubrova and Muzio algebra 2270: 2253: 2237: 2199: 2167: 2150:G3 logic), introduced by 2031: 2014: 1998: 1828: 1783: 1738: 1531: 1517: 1514: 1498: 1454: 1437: 1421: 1326: 1312: 1309: 1293: 1249: 1232: 1216: 1197:, and its truth table is 978: 964: 931: 905: 891: 858: 832: 818: 785: 765: 757: 749: 729: 693: 660: 620: 587: 547: 514: 486: 458: 306:skew binary number system 197:Grigore Constantin Moisil 173:) which provide only for 2867:The Philosophical Review 2861:Taylor, Richard (1957). 2245: 2186: 2183: 2006: 1901:law of non-contradiction 1857:In Łukasiewicz's Ł3 the 1810: 1805: 1765: 1760: 1720: 1715: 1509: 1506: 1503: 1429: 1304: 1301: 1298: 1224: 1070:values, are assigned to 1066:If numeric values, e.g. 942: 939: 936: 869: 866: 863: 796: 793: 790: 744: 741: 668: 595: 522: 473: 470: 431:Kleene and Priest logics 375:to a trivalent context. 261:Representation of values 217:many-valued logic system 203:-valued logics in 1945. 145:, sometimes abbreviated 4931:Self-verifying theories 4752:Tarski's axiomatization 3703:Tarski's undefinability 3698:incompleteness theorems 3331:Constructive set theory 3190:Dubrova, Elena (2002). 2358:HT logic is the unique 453:'s "logic of paradox". 5305:Mathematics portal 4916:Proof of impossibility 4564:propositional variable 3874:Propositional calculus 3133:Grzegorz Malinowski, " 3111:Standard Ternary Logic 3083:Nelson, David (2008). 2600:Post, Emil L. (1921). 2585:. Stanford NLP Group. 2540:Ternary numeral system 2391:This section is empty. 1943:law of excluded fourth 1887:law of excluded middle 1491:(A, B), MIN(1, 1−A+B) 1191: 289:ternary numeral system 267:ternary numeral system 247: 213:Charles Sanders Peirce 5174:Kolmogorov complexity 5127:Computably enumerable 5027:Model complete theory 4819:Principia Mathematica 3879:Propositional formula 3708:Banach–Tarski paradox 3316:Constructive analysis 2960:Philosophical Studies 2929:Philosophical Studies 2914:10.1515/sem-2019-0115 2822:Prior, A. N. (1953). 2132:Further information: 2126:Further information: 1385:Further information: 1192: 425:functionally complete 418:), and 4 variants of 193:Clarence Irving Lewis 5122:Church–Turing thesis 5109:Computability theory 4318:continuum hypothesis 3836:Square of opposition 3694:Gödel's completeness 3369:Fuzzy set operations 3364:Fuzzy finite element 3311:Intuitionistic logic 3056:10.1511/2001.40.3268 2433:modulars arithmetics 2353:intuitionistic logic 2158:, is a three-valued 2156:intuitionistic logic 1107: 149:) is any of several 58:"Three-valued logic" 43:improve this article 5276:Mathematical object 5167:P versus NP problem 5132:Computable function 4926:Reverse mathematics 4852:Logical consequence 4729:primitive recursive 4724:elementary function 4497:Free/bound variable 4350:Tarski–Grothendieck 3869:Logical connectives 3799:Logical equivalence 3649:Logical consequence 3546:Non-monotonic logic 3295:Non-classical logic 2583:Stanford University 2560:The World of Null-A 2231: 2180: 1992: 1492: 1415: 1287: 1286:(A, B), MAX(−A, B) 1210: 925: 852: 779: 738: 654: 581: 508: 467: 447:Stephen Cole Kleene 369:propositional logic 251:Stephen Cole Kleene 5074:Transfer principle 5037:Semantics of logic 5022:Categorical theory 4998:Non-standard model 4512:Logical connective 3639:Information theory 3588:Mathematical logic 3541:Intermediate logic 3321:Heyting arithmetic 3109:Douglas W. Jones, 3039:American Scientist 2972:10.1007/BF02304905 2941:10.1007/BF00996317 2666:plato.stanford.edu 2414:Ternary Post logic 2225: 2174: 2160:intermediate logic 2128:Intermediate logic 1986: 1486: 1409: 1281: 1209:(A, B), OR(¬A, B) 1204: 1187: 1164: 1151: 1140: 923: 850: 777: 736: 652: 579: 506: 465: 441:Below is a set of 127:three-valued logic 5330:Ternary computers 5325:Many-valued logic 5312: 5311: 5244:Abstract category 5047:Theories of truth 4857:Rule of inference 4847:Natural deduction 4828: 4827: 4373: 4372: 4078:Cartesian product 3983: 3982: 3889:Many-valued logic 3864:Boolean functions 3747:Russell's paradox 3722:diagonal argument 3619:First-order logic 3554: 3553: 3536:Inquisitive logic 3531:Dynamic semantics 3484:Three-state logic 3438:Ontology language 3224:978-0-521-88128-9 3177:978-1-59829-190-2 2685:Lane, R. (2001). 2550:Three-state logic 2519:Four-valued logic 2491:Philosophy portal 2411: 2410: 2351:to the axioms of 2302: 2301: 2298: 2297: 2219: 2218: 2215: 2214: 2063: 2062: 2059: 2058: 1848: 1847: 1844: 1843: 1799: 1798: 1754: 1753: 1563: 1562: 1559: 1558: 1482: 1481: 1387:Łukasiewicz logic 1381:Łukasiewicz logic 1358: 1357: 1354: 1353: 1277: 1276: 1180: 1163: 1158: 1150: 1145: 1141: 1128: 1127: 1121: 996: 995: 992: 991: 919: 918: 846: 845: 773: 772: 725: 724: 721: 720: 648: 647: 575: 574: 502: 501: 151:many-valued logic 119: 118: 111: 93: 5337: 5303: 5302: 5254:History of logic 5249:Category of sets 5142:Decision problem 4921:Ordinal analysis 4862:Sequent calculus 4760:Boolean algebras 4700: 4699: 4674: 4645:logical/constant 4399: 4385: 4308:Zermelo–Fraenkel 4059:Set operations: 3994: 3931: 3762: 3742:Löwenheim–Skolem 3629:Formal semantics 3581: 3574: 3567: 3558: 3489:Tri-state buffer 3288: 3281: 3274: 3265: 3235: 3233: 3231: 3199: 3188: 3182: 3181: 3163: 3157: 3156: 3148: 3142: 3141:, Elsevier, 2009 3131: 3125: 3120: 3114: 3113:, Feb. 11, 2013. 3107: 3101: 3100: 3080: 3074: 3073: 3071: 3070: 3064: 3035: 3023: 3017: 3016: 3009:Knuth, Donald E. 3005: 2999: 2998: 2986: 2980: 2979: 2977:to the evidence. 2955: 2949: 2948: 2924: 2918: 2917: 2908:(240): 129–143. 2897: 2891: 2890: 2858: 2852: 2851: 2819: 2813: 2812: 2792: 2781: 2780: 2778: 2777: 2762: 2756: 2755: 2753: 2751: 2735: 2729: 2728: 2723: 2721: 2705: 2699: 2698: 2682: 2676: 2675: 2673: 2672: 2658: 2652: 2651: 2649: 2631: 2621: 2597: 2591: 2590: 2575: 2554:tri-state buffer 2544:Balanced ternary 2509:Boolean function 2493: 2488: 2487: 2486: 2427:Modular algebras 2406: 2403: 2393:You can help by 2386: 2379: 2350: 2332:or equivalently 2331: 2232: 2221: 2181: 2165: 2113: 2104: 2083: 1993: 1982: 1965: 1940: 1920: 1914: 1898: 1884: 1874: 1859:designated value 1816: 1808: 1803: 1771: 1763: 1758: 1726: 1718: 1713: 1709: 1702: 1678: 1660: 1637: 1609: 1589: 1493: 1416: 1405: 1371:Logic of Paradox 1288: 1211: 1200: 1196: 1194: 1193: 1188: 1178: 1165: 1161: 1156: 1152: 1148: 1143: 1142: 1139: 1123: 1119: 1068:balanced ternary 926: 853: 780: 739: 727: 655: 582: 509: 468: 456: 358:ternary computer 275:balanced ternary 234:Bruno de Finetti 114: 107: 103: 100: 94: 92: 51: 27: 19: 5345: 5344: 5340: 5339: 5338: 5336: 5335: 5334: 5315: 5314: 5313: 5308: 5297: 5290: 5235:Category theory 5225:Algebraic logic 5208: 5179:Lambda calculus 5117:Church encoding 5103: 5079:Truth predicate 4935: 4901:Complete theory 4824: 4693: 4689: 4685: 4680: 4672: 4392: and  4388: 4383: 4369: 4345:New Foundations 4313:axiom of choice 4296: 4258:Gödel numbering 4198: and  4190: 4094: 3979: 3929: 3910: 3859:Boolean algebra 3845: 3809:Equiconsistency 3774:Classical logic 3751: 3732:Halting problem 3720: and  3696: and  3684: and  3683: 3678:Theorems ( 3673: 3590: 3585: 3555: 3550: 3519: 3470: 3442: 3419: 3401: 3392:Relevance logic 3387:Structural rule 3373: 3349:Degree of truth 3335: 3297: 3292: 3229: 3227: 3225: 3210: 3207: 3205:Further reading 3202: 3189: 3185: 3178: 3165: 3164: 3160: 3150: 3149: 3145: 3132: 3128: 3121: 3117: 3108: 3104: 3097: 3082: 3081: 3077: 3068: 3066: 3062: 3033: 3025: 3024: 3020: 3007: 3006: 3002: 2988: 2987: 2983: 2957: 2956: 2952: 2926: 2925: 2921: 2899: 2898: 2894: 2879:10.2307/2182851 2860: 2859: 2855: 2840:10.2307/2217099 2834:(13): 317–326. 2821: 2820: 2816: 2794: 2793: 2784: 2775: 2773: 2767:"Triadic Logic" 2764: 2763: 2759: 2749: 2747: 2737: 2736: 2732: 2719: 2717: 2707: 2706: 2702: 2687:"Triadic Logic" 2684: 2683: 2679: 2670: 2668: 2660: 2659: 2655: 2619:10.2307/2370324 2599: 2598: 2594: 2577: 2576: 2572: 2568: 2514:Digital circuit 2489: 2484: 2482: 2479: 2463: 2457: 2452: 2442:Pradhan algebra 2429: 2416: 2407: 2401: 2398: 2374: 2368: 2333: 2305: 2229: 2178: 2136: 2130: 2124: 2109: 2091: 2069: 1990: 1977: 1948: 1925: 1916: 1904: 1890: 1876: 1866: 1865:. For example, 1811: 1806: 1766: 1761: 1721: 1716: 1681: 1663: 1645: 1612: 1592: 1569: 1490: 1413: 1389: 1383: 1285: 1208: 1105: 1104: 439: 433: 388:unary operators 381: 362:ternary signals 263: 225: 209: 189:Jan Łukasiewicz 115: 104: 98: 95: 52: 50: 40: 28: 17: 12: 11: 5: 5343: 5341: 5333: 5332: 5327: 5317: 5316: 5310: 5309: 5295: 5292: 5291: 5289: 5288: 5283: 5278: 5273: 5268: 5267: 5266: 5256: 5251: 5246: 5237: 5232: 5227: 5222: 5220:Abstract logic 5216: 5214: 5210: 5209: 5207: 5206: 5201: 5199:Turing machine 5196: 5191: 5186: 5181: 5176: 5171: 5170: 5169: 5164: 5159: 5154: 5149: 5139: 5137:Computable set 5134: 5129: 5124: 5119: 5113: 5111: 5105: 5104: 5102: 5101: 5096: 5091: 5086: 5081: 5076: 5071: 5066: 5065: 5064: 5059: 5054: 5044: 5039: 5034: 5032:Satisfiability 5029: 5024: 5019: 5018: 5017: 5007: 5006: 5005: 4995: 4994: 4993: 4988: 4983: 4978: 4973: 4963: 4962: 4961: 4956: 4949:Interpretation 4945: 4943: 4937: 4936: 4934: 4933: 4928: 4923: 4918: 4913: 4903: 4898: 4897: 4896: 4895: 4894: 4884: 4879: 4869: 4864: 4859: 4854: 4849: 4844: 4838: 4836: 4830: 4829: 4826: 4825: 4823: 4822: 4814: 4813: 4812: 4811: 4806: 4805: 4804: 4799: 4794: 4774: 4773: 4772: 4770:minimal axioms 4767: 4756: 4755: 4754: 4743: 4742: 4741: 4736: 4731: 4726: 4721: 4716: 4703: 4701: 4682: 4681: 4679: 4678: 4677: 4676: 4664: 4659: 4658: 4657: 4652: 4647: 4642: 4632: 4627: 4622: 4617: 4616: 4615: 4610: 4600: 4599: 4598: 4593: 4588: 4583: 4573: 4568: 4567: 4566: 4561: 4556: 4546: 4545: 4544: 4539: 4534: 4529: 4524: 4519: 4509: 4504: 4499: 4494: 4493: 4492: 4487: 4482: 4477: 4467: 4462: 4460:Formation rule 4457: 4452: 4451: 4450: 4445: 4435: 4434: 4433: 4423: 4418: 4413: 4408: 4402: 4396: 4379:Formal systems 4375: 4374: 4371: 4370: 4368: 4367: 4362: 4357: 4352: 4347: 4342: 4337: 4332: 4327: 4322: 4321: 4320: 4315: 4304: 4302: 4298: 4297: 4295: 4294: 4293: 4292: 4282: 4277: 4276: 4275: 4268:Large cardinal 4265: 4260: 4255: 4250: 4245: 4231: 4230: 4229: 4224: 4219: 4204: 4202: 4192: 4191: 4189: 4188: 4187: 4186: 4181: 4176: 4166: 4161: 4156: 4151: 4146: 4141: 4136: 4131: 4126: 4121: 4116: 4111: 4105: 4103: 4096: 4095: 4093: 4092: 4091: 4090: 4085: 4080: 4075: 4070: 4065: 4057: 4056: 4055: 4050: 4040: 4035: 4033:Extensionality 4030: 4028:Ordinal number 4025: 4015: 4010: 4009: 4008: 3997: 3991: 3985: 3984: 3981: 3980: 3978: 3977: 3972: 3967: 3962: 3957: 3952: 3947: 3946: 3945: 3935: 3934: 3933: 3920: 3918: 3912: 3911: 3909: 3908: 3907: 3906: 3901: 3896: 3886: 3881: 3876: 3871: 3866: 3861: 3855: 3853: 3847: 3846: 3844: 3843: 3838: 3833: 3828: 3823: 3818: 3813: 3812: 3811: 3801: 3796: 3791: 3786: 3781: 3776: 3770: 3768: 3759: 3753: 3752: 3750: 3749: 3744: 3739: 3734: 3729: 3724: 3712:Cantor's  3710: 3705: 3700: 3690: 3688: 3675: 3674: 3672: 3671: 3666: 3661: 3656: 3651: 3646: 3641: 3636: 3631: 3626: 3621: 3616: 3611: 3610: 3609: 3598: 3596: 3592: 3591: 3586: 3584: 3583: 3576: 3569: 3561: 3552: 3551: 3549: 3548: 3543: 3538: 3533: 3527: 3525: 3521: 3520: 3518: 3517: 3516: 3515: 3505: 3504: 3503: 3493: 3492: 3491: 3480: 3478: 3472: 3471: 3469: 3468: 3463: 3458: 3452: 3450: 3444: 3443: 3441: 3440: 3435: 3429: 3427: 3421: 3420: 3418: 3417: 3411: 3409: 3407:Paraconsistent 3403: 3402: 3400: 3399: 3394: 3389: 3383: 3381: 3375: 3374: 3372: 3371: 3366: 3361: 3356: 3351: 3345: 3343: 3337: 3336: 3334: 3333: 3328: 3323: 3318: 3313: 3307: 3305: 3303:Intuitionistic 3299: 3298: 3293: 3291: 3290: 3283: 3276: 3268: 3262: 3261: 3247: 3237: 3236:, chapters 5-9 3223: 3206: 3203: 3201: 3200: 3183: 3176: 3158: 3143: 3126: 3115: 3102: 3095: 3075: 3018: 3000: 2981: 2950: 2935:(1): 181–190. 2919: 2892: 2853: 2814: 2782: 2765:Lane, Robert. 2757: 2730: 2700: 2677: 2653: 2612:(3): 163–185. 2592: 2569: 2567: 2564: 2563: 2562: 2557: 2547: 2537: 2531: 2526: 2521: 2516: 2511: 2506: 2501: 2495: 2494: 2478: 2475: 2459:Main article: 2456: 2453: 2451: 2448: 2447: 2446: 2443: 2440: 2428: 2425: 2424: 2423: 2420: 2415: 2412: 2409: 2408: 2389: 2387: 2370:Main article: 2367: 2364: 2300: 2299: 2296: 2295: 2292: 2289: 2286: 2282: 2281: 2278: 2275: 2272: 2268: 2267: 2264: 2261: 2258: 2255: 2251: 2250: 2247: 2244: 2240: 2239: 2236: 2227: 2217: 2216: 2213: 2212: 2209: 2205: 2204: 2201: 2197: 2196: 2193: 2189: 2188: 2185: 2176: 2170: 2169: 2123: 2120: 2106: 2105: 2085: 2084: 2061: 2060: 2057: 2056: 2053: 2050: 2047: 2043: 2042: 2039: 2036: 2033: 2029: 2028: 2025: 2022: 2019: 2016: 2012: 2011: 2008: 2005: 2001: 2000: 1997: 1988: 1976: 1973: 1972: 1971: 1946: 1846: 1845: 1842: 1841: 1838: 1834: 1833: 1830: 1826: 1825: 1822: 1818: 1817: 1809: 1800: 1797: 1796: 1793: 1789: 1788: 1785: 1781: 1780: 1777: 1773: 1772: 1764: 1755: 1752: 1751: 1748: 1744: 1743: 1740: 1736: 1735: 1732: 1728: 1727: 1719: 1704: 1703: 1679: 1661: 1639: 1638: 1610: 1590: 1561: 1560: 1557: 1556: 1553: 1550: 1547: 1543: 1542: 1539: 1536: 1533: 1529: 1528: 1525: 1522: 1519: 1516: 1512: 1511: 1508: 1505: 1501: 1500: 1497: 1488: 1483: 1480: 1479: 1476: 1473: 1470: 1466: 1465: 1462: 1459: 1456: 1452: 1451: 1448: 1445: 1442: 1439: 1435: 1434: 1431: 1428: 1424: 1423: 1420: 1411: 1382: 1379: 1356: 1355: 1352: 1351: 1348: 1345: 1342: 1338: 1337: 1334: 1331: 1328: 1324: 1323: 1320: 1317: 1314: 1311: 1307: 1306: 1303: 1300: 1296: 1295: 1292: 1283: 1278: 1275: 1274: 1271: 1268: 1265: 1261: 1260: 1257: 1254: 1251: 1247: 1246: 1243: 1240: 1237: 1234: 1230: 1229: 1226: 1223: 1219: 1218: 1215: 1206: 1186: 1183: 1177: 1174: 1171: 1168: 1155: 1138: 1135: 1132: 1126: 1118: 1115: 1112: 994: 993: 990: 989: 986: 983: 980: 976: 975: 972: 969: 966: 962: 961: 958: 955: 952: 949: 945: 944: 941: 938: 934: 933: 930: 920: 917: 916: 913: 910: 907: 903: 902: 899: 896: 893: 889: 888: 885: 882: 879: 876: 872: 871: 868: 865: 861: 860: 857: 847: 844: 843: 840: 837: 834: 830: 829: 826: 823: 820: 816: 815: 812: 809: 806: 803: 799: 798: 795: 792: 788: 787: 784: 774: 771: 770: 767: 763: 762: 759: 755: 754: 751: 747: 746: 743: 732: 731: 723: 722: 719: 718: 715: 712: 709: 705: 704: 701: 698: 695: 691: 690: 687: 684: 681: 678: 674: 673: 670: 667: 663: 662: 659: 649: 646: 645: 642: 639: 636: 632: 631: 628: 625: 622: 618: 617: 614: 611: 608: 605: 601: 600: 597: 594: 590: 589: 586: 576: 573: 572: 569: 566: 563: 559: 558: 555: 552: 549: 545: 544: 541: 538: 535: 532: 528: 527: 524: 521: 517: 516: 513: 503: 500: 499: 496: 492: 491: 488: 484: 483: 480: 476: 475: 472: 461: 460: 432: 429: 380: 377: 354: 353: 342: 309: 302: 285: 278: 262: 259: 224: 221: 208: 205: 185:Emil Leon Post 117: 116: 31: 29: 22: 15: 13: 10: 9: 6: 4: 3: 2: 5342: 5331: 5328: 5326: 5323: 5322: 5320: 5307: 5306: 5301: 5293: 5287: 5284: 5282: 5279: 5277: 5274: 5272: 5269: 5265: 5262: 5261: 5260: 5257: 5255: 5252: 5250: 5247: 5245: 5241: 5238: 5236: 5233: 5231: 5228: 5226: 5223: 5221: 5218: 5217: 5215: 5211: 5205: 5202: 5200: 5197: 5195: 5194:Recursive set 5192: 5190: 5187: 5185: 5182: 5180: 5177: 5175: 5172: 5168: 5165: 5163: 5160: 5158: 5155: 5153: 5150: 5148: 5145: 5144: 5143: 5140: 5138: 5135: 5133: 5130: 5128: 5125: 5123: 5120: 5118: 5115: 5114: 5112: 5110: 5106: 5100: 5097: 5095: 5092: 5090: 5087: 5085: 5082: 5080: 5077: 5075: 5072: 5070: 5067: 5063: 5060: 5058: 5055: 5053: 5050: 5049: 5048: 5045: 5043: 5040: 5038: 5035: 5033: 5030: 5028: 5025: 5023: 5020: 5016: 5013: 5012: 5011: 5008: 5004: 5003:of arithmetic 5001: 5000: 4999: 4996: 4992: 4989: 4987: 4984: 4982: 4979: 4977: 4974: 4972: 4969: 4968: 4967: 4964: 4960: 4957: 4955: 4952: 4951: 4950: 4947: 4946: 4944: 4942: 4938: 4932: 4929: 4927: 4924: 4922: 4919: 4917: 4914: 4911: 4910:from ZFC 4907: 4904: 4902: 4899: 4893: 4890: 4889: 4888: 4885: 4883: 4880: 4878: 4875: 4874: 4873: 4870: 4868: 4865: 4863: 4860: 4858: 4855: 4853: 4850: 4848: 4845: 4843: 4840: 4839: 4837: 4835: 4831: 4821: 4820: 4816: 4815: 4810: 4809:non-Euclidean 4807: 4803: 4800: 4798: 4795: 4793: 4792: 4788: 4787: 4785: 4782: 4781: 4779: 4775: 4771: 4768: 4766: 4763: 4762: 4761: 4757: 4753: 4750: 4749: 4748: 4744: 4740: 4737: 4735: 4732: 4730: 4727: 4725: 4722: 4720: 4717: 4715: 4712: 4711: 4709: 4705: 4704: 4702: 4697: 4691: 4686:Example  4683: 4675: 4670: 4669: 4668: 4665: 4663: 4660: 4656: 4653: 4651: 4648: 4646: 4643: 4641: 4638: 4637: 4636: 4633: 4631: 4628: 4626: 4623: 4621: 4618: 4614: 4611: 4609: 4606: 4605: 4604: 4601: 4597: 4594: 4592: 4589: 4587: 4584: 4582: 4579: 4578: 4577: 4574: 4572: 4569: 4565: 4562: 4560: 4557: 4555: 4552: 4551: 4550: 4547: 4543: 4540: 4538: 4535: 4533: 4530: 4528: 4525: 4523: 4520: 4518: 4515: 4514: 4513: 4510: 4508: 4505: 4503: 4500: 4498: 4495: 4491: 4488: 4486: 4483: 4481: 4478: 4476: 4473: 4472: 4471: 4468: 4466: 4463: 4461: 4458: 4456: 4453: 4449: 4446: 4444: 4443:by definition 4441: 4440: 4439: 4436: 4432: 4429: 4428: 4427: 4424: 4422: 4419: 4417: 4414: 4412: 4409: 4407: 4404: 4403: 4400: 4397: 4395: 4391: 4386: 4380: 4376: 4366: 4363: 4361: 4358: 4356: 4353: 4351: 4348: 4346: 4343: 4341: 4338: 4336: 4333: 4331: 4330:Kripke–Platek 4328: 4326: 4323: 4319: 4316: 4314: 4311: 4310: 4309: 4306: 4305: 4303: 4299: 4291: 4288: 4287: 4286: 4283: 4281: 4278: 4274: 4271: 4270: 4269: 4266: 4264: 4261: 4259: 4256: 4254: 4251: 4249: 4246: 4243: 4239: 4235: 4232: 4228: 4225: 4223: 4220: 4218: 4215: 4214: 4213: 4209: 4206: 4205: 4203: 4201: 4197: 4193: 4185: 4182: 4180: 4177: 4175: 4174:constructible 4172: 4171: 4170: 4167: 4165: 4162: 4160: 4157: 4155: 4152: 4150: 4147: 4145: 4142: 4140: 4137: 4135: 4132: 4130: 4127: 4125: 4122: 4120: 4117: 4115: 4112: 4110: 4107: 4106: 4104: 4102: 4097: 4089: 4086: 4084: 4081: 4079: 4076: 4074: 4071: 4069: 4066: 4064: 4061: 4060: 4058: 4054: 4051: 4049: 4046: 4045: 4044: 4041: 4039: 4036: 4034: 4031: 4029: 4026: 4024: 4020: 4016: 4014: 4011: 4007: 4004: 4003: 4002: 3999: 3998: 3995: 3992: 3990: 3986: 3976: 3973: 3971: 3968: 3966: 3963: 3961: 3958: 3956: 3953: 3951: 3948: 3944: 3941: 3940: 3939: 3936: 3932: 3927: 3926: 3925: 3922: 3921: 3919: 3917: 3913: 3905: 3902: 3900: 3897: 3895: 3892: 3891: 3890: 3887: 3885: 3882: 3880: 3877: 3875: 3872: 3870: 3867: 3865: 3862: 3860: 3857: 3856: 3854: 3852: 3851:Propositional 3848: 3842: 3839: 3837: 3834: 3832: 3829: 3827: 3824: 3822: 3819: 3817: 3814: 3810: 3807: 3806: 3805: 3802: 3800: 3797: 3795: 3792: 3790: 3787: 3785: 3782: 3780: 3779:Logical truth 3777: 3775: 3772: 3771: 3769: 3767: 3763: 3760: 3758: 3754: 3748: 3745: 3743: 3740: 3738: 3735: 3733: 3730: 3728: 3725: 3723: 3719: 3715: 3711: 3709: 3706: 3704: 3701: 3699: 3695: 3692: 3691: 3689: 3687: 3681: 3676: 3670: 3667: 3665: 3662: 3660: 3657: 3655: 3652: 3650: 3647: 3645: 3642: 3640: 3637: 3635: 3632: 3630: 3627: 3625: 3622: 3620: 3617: 3615: 3612: 3608: 3605: 3604: 3603: 3600: 3599: 3597: 3593: 3589: 3582: 3577: 3575: 3570: 3568: 3563: 3562: 3559: 3547: 3544: 3542: 3539: 3537: 3534: 3532: 3529: 3528: 3526: 3522: 3514: 3511: 3510: 3509: 3506: 3502: 3499: 3498: 3497: 3494: 3490: 3487: 3486: 3485: 3482: 3481: 3479: 3477: 3476:Digital logic 3473: 3467: 3464: 3462: 3459: 3457: 3454: 3453: 3451: 3449: 3445: 3439: 3436: 3434: 3431: 3430: 3428: 3426: 3422: 3416: 3413: 3412: 3410: 3408: 3404: 3398: 3395: 3393: 3390: 3388: 3385: 3384: 3382: 3380: 3379:Substructural 3376: 3370: 3367: 3365: 3362: 3360: 3357: 3355: 3352: 3350: 3347: 3346: 3344: 3342: 3338: 3332: 3329: 3327: 3324: 3322: 3319: 3317: 3314: 3312: 3309: 3308: 3306: 3304: 3300: 3296: 3289: 3284: 3282: 3277: 3275: 3270: 3269: 3266: 3260: 3259:0-486-40459-5 3256: 3252: 3248: 3246: 3242: 3238: 3226: 3220: 3216: 3215: 3209: 3208: 3204: 3197: 3193: 3187: 3184: 3179: 3173: 3169: 3162: 3159: 3154: 3147: 3144: 3140: 3136: 3130: 3127: 3124: 3119: 3116: 3112: 3106: 3103: 3098: 3096:9780141920870 3092: 3088: 3087: 3079: 3076: 3061: 3057: 3053: 3049: 3045: 3041: 3040: 3032: 3028: 3022: 3019: 3014: 3010: 3004: 3001: 2997: 2992: 2985: 2982: 2978: 2973: 2969: 2965: 2961: 2954: 2951: 2947: 2942: 2938: 2934: 2930: 2923: 2920: 2915: 2911: 2907: 2903: 2896: 2893: 2888: 2884: 2880: 2876: 2872: 2868: 2864: 2857: 2854: 2849: 2845: 2841: 2837: 2833: 2829: 2825: 2818: 2815: 2810: 2806: 2803:(1–2): 1–11. 2802: 2798: 2791: 2789: 2787: 2783: 2772: 2768: 2761: 2758: 2745: 2741: 2734: 2731: 2727: 2715: 2711: 2704: 2701: 2696: 2692: 2688: 2681: 2678: 2667: 2663: 2657: 2654: 2648: 2643: 2639: 2635: 2630: 2625: 2620: 2615: 2611: 2607: 2603: 2596: 2593: 2588: 2584: 2580: 2574: 2571: 2565: 2561: 2558: 2555: 2551: 2548: 2545: 2541: 2538: 2535: 2532: 2530: 2527: 2525: 2522: 2520: 2517: 2515: 2512: 2510: 2507: 2505: 2502: 2500: 2497: 2496: 2492: 2481: 2476: 2474: 2472: 2468: 2462: 2454: 2449: 2444: 2441: 2438: 2437: 2436: 2434: 2426: 2421: 2418: 2417: 2413: 2405: 2396: 2392: 2388: 2385: 2381: 2380: 2377: 2373: 2366:Bochvar logic 2365: 2363: 2361: 2356: 2354: 2348: 2344: 2340: 2336: 2329: 2325: 2321: 2317: 2313: 2309: 2293: 2290: 2287: 2283: 2279: 2276: 2273: 2269: 2265: 2262: 2259: 2252: 2241: 2233: 2223: 2210: 2206: 2202: 2198: 2194: 2190: 2182: 2172: 2166: 2163: 2161: 2157: 2153: 2149: 2145: 2141: 2135: 2129: 2121: 2119: 2117: 2112: 2103: 2099: 2095: 2090: 2089: 2088: 2081: 2077: 2073: 2068: 2067: 2066: 2054: 2051: 2048: 2044: 2040: 2037: 2034: 2030: 2026: 2023: 2020: 2013: 2002: 1994: 1984: 1980: 1974: 1969: 1963: 1959: 1956: 1952: 1947: 1944: 1939: 1935: 1932: 1928: 1924: 1923: 1922: 1919: 1912: 1908: 1902: 1897: 1893: 1888: 1883: 1879: 1873: 1869: 1864: 1860: 1855: 1853: 1839: 1835: 1831: 1827: 1823: 1819: 1815: 1804: 1801: 1794: 1790: 1786: 1782: 1778: 1774: 1770: 1759: 1756: 1749: 1745: 1741: 1737: 1733: 1729: 1725: 1714: 1711: 1707: 1701: 1698: 1694: 1691: 1687: 1684: 1680: 1677: 1673: 1669: 1666: 1662: 1659: 1655: 1651: 1648: 1644: 1643: 1642: 1635: 1631: 1627: 1623: 1619: 1615: 1611: 1607: 1603: 1599: 1595: 1591: 1588: 1584: 1580: 1576: 1572: 1568: 1567: 1566: 1554: 1551: 1548: 1544: 1540: 1537: 1534: 1530: 1526: 1523: 1520: 1513: 1502: 1494: 1484: 1477: 1474: 1471: 1467: 1463: 1460: 1457: 1453: 1449: 1446: 1443: 1436: 1425: 1417: 1407: 1403: 1400: 1398: 1394: 1388: 1380: 1378: 1376: 1372: 1367: 1361: 1349: 1346: 1343: 1339: 1335: 1332: 1329: 1325: 1321: 1318: 1315: 1308: 1297: 1289: 1279: 1272: 1269: 1266: 1262: 1258: 1255: 1252: 1248: 1244: 1241: 1238: 1231: 1220: 1212: 1202: 1198: 1181: 1175: 1169: 1124: 1116: 1110: 1102: 1099: 1097: 1094:is less than 1093: 1089: 1086:is less than 1085: 1081: 1077: 1073: 1069: 1064: 1062: 1058: 1054: 1050: 1046: 1042: 1038: 1034: 1030: 1026: 1022: 1018: 1014: 1010: 1006: 1001: 987: 984: 981: 977: 973: 970: 967: 963: 959: 956: 953: 946: 935: 927: 921: 914: 911: 908: 904: 900: 897: 894: 890: 886: 883: 880: 873: 862: 854: 848: 841: 838: 835: 831: 827: 824: 821: 817: 813: 810: 807: 800: 789: 781: 775: 768: 764: 760: 756: 752: 748: 740: 734: 728: 716: 713: 710: 706: 702: 699: 696: 692: 688: 685: 682: 675: 664: 656: 650: 643: 640: 637: 633: 629: 626: 623: 619: 615: 612: 609: 602: 591: 583: 577: 570: 567: 564: 560: 556: 553: 550: 546: 542: 539: 536: 529: 518: 510: 504: 497: 493: 489: 485: 481: 477: 469: 463: 457: 454: 452: 451:Graham Priest 448: 444: 438: 430: 428: 426: 421: 417: 413: 409: 405: 401: 397: 393: 389: 386:allows 2 = 4 385: 384:Boolean logic 378: 376: 374: 370: 365: 363: 359: 351: 347: 343: 340: 336: 332: 331: 326: 322: 318: 314: 310: 307: 303: 300: 299: 294: 290: 286: 283: 279: 276: 272: 271: 270: 268: 260: 258: 256: 252: 246: 241: 239: 238:Hilary Putnam 235: 231: 222: 220: 218: 214: 211:Around 1910, 207:Pre-discovery 206: 204: 202: 198: 194: 190: 186: 182: 180: 176: 172: 171:Boolean logic 168: 164: 160: 156: 152: 148: 144: 140: 136: 132: 131:trinary logic 128: 124: 113: 110: 102: 91: 88: 84: 81: 77: 74: 70: 67: 63: 60: –  59: 55: 54:Find sources: 48: 44: 38: 37: 32:This article 30: 26: 21: 20: 5296: 5094:Ultraproduct 4941:Model theory 4906:Independence 4842:Formal proof 4834:Proof theory 4817: 4790: 4747:real numbers 4719:second-order 4630:Substitution 4507:Metalanguage 4448:conservative 4421:Axiom schema 4365:Constructive 4335:Morse–Kelley 4301:Set theories 4280:Aleph number 4273:inaccessible 4179:Grothendieck 4063:intersection 3950:Higher-order 3938:Second-order 3893: 3884:Truth tables 3841:Venn diagram 3624:Formal proof 3456:Three-valued 3455: 3397:Linear logic 3250: 3228:. Retrieved 3213: 3195: 3186: 3167: 3161: 3153:Sitz. Berlin 3152: 3146: 3138: 3129: 3118: 3105: 3085: 3078: 3067:. Retrieved 3043: 3037: 3031:"Third base" 3027:Hayes, Brian 3021: 3012: 3003: 2994: 2990: 2984: 2975: 2966:(5): 73–80. 2963: 2959: 2953: 2944: 2932: 2928: 2922: 2905: 2901: 2895: 2870: 2866: 2856: 2831: 2827: 2817: 2800: 2796: 2774:. Retrieved 2770: 2760: 2748:. Retrieved 2743: 2733: 2725: 2718:. Retrieved 2713: 2703: 2690: 2680: 2669:. Retrieved 2665: 2656: 2609: 2605: 2595: 2582: 2573: 2464: 2450:Applications 2439:Cohn algebra 2430: 2399: 2395:adding to it 2390: 2375: 2357: 2346: 2342: 2338: 2334: 2327: 2323: 2319: 2315: 2311: 2307: 2303: 2143: 2139: 2137: 2110: 2107: 2101: 2097: 2093: 2086: 2079: 2075: 2071: 2064: 1978: 1961: 1957: 1954: 1950: 1937: 1933: 1930: 1926: 1917: 1910: 1906: 1895: 1891: 1881: 1877: 1871: 1867: 1856: 1849: 1813: 1768: 1723: 1705: 1699: 1696: 1692: 1689: 1685: 1682: 1675: 1671: 1667: 1664: 1657: 1653: 1649: 1646: 1640: 1633: 1629: 1625: 1621: 1617: 1613: 1605: 1601: 1597: 1593: 1586: 1582: 1578: 1574: 1570: 1564: 1401: 1396: 1392: 1390: 1374: 1365: 1362: 1359: 1103: 1100: 1095: 1091: 1087: 1083: 1079: 1075: 1071: 1065: 1060: 1056: 1052: 1048: 1044: 1040: 1039:also equals 1036: 1032: 1028: 1024: 1020: 1016: 1012: 1008: 1004: 999: 997: 443:truth tables 440: 382: 366: 355: 349: 345: 338: 334: 328: 324: 320: 319:, and 0 for 316: 312: 296: 264: 248: 243: 226: 210: 200: 183: 178: 174: 162: 158: 155:truth values 146: 142: 138: 134: 130: 126: 120: 105: 99:January 2011 96: 86: 79: 72: 65: 53: 41:Please help 36:verification 33: 5204:Type theory 5152:undecidable 5084:Truth value 4971:equivalence 4650:non-logical 4263:Enumeration 4253:Isomorphism 4200:cardinality 4184:Von Neumann 4149:Ultrafilter 4114:Uncountable 4048:equivalence 3965:Quantifiers 3955:Fixed-point 3924:First-order 3804:Consistency 3789:Proposition 3766:Traditional 3737:Lindström's 3727:Compactness 3669:Type theory 3614:Cardinality 3496:Four-valued 3466:Łukasiewicz 3461:Four-valued 3448:Many-valued 3425:Description 3415:Dialetheism 2873:(1): 1–28. 2402:August 2014 1852:modal logic 420:implication 416:equivalence 373:connectives 330:undecidable 249:Similarly, 157:indicating 5319:Categories 5015:elementary 4708:arithmetic 4576:Quantifier 4554:functional 4426:Expression 4144:Transitive 4088:identities 4073:complement 4006:hereditary 3989:Set theory 3354:Fuzzy rule 3069:2020-04-12 2776:2020-07-30 2671:2024-05-15 2566:References 2461:Null (SQL) 1899:, and the 1375:designated 1366:designated 1082:such that 851:MAX(A, B) 778:MIN(A, B) 653:XOR(A, B) 507:AND(A, B) 435:See also: 335:irrelevant 325:unknowable 255:predicates 223:Motivation 215:defined a 69:newspapers 5286:Supertask 5189:Recursion 5147:decidable 4981:saturated 4959:of models 4882:deductive 4877:axiomatic 4797:Hilbert's 4784:Euclidean 4765:canonical 4688:axiomatic 4620:Signature 4549:Predicate 4438:Extension 4360:Ackermann 4285:Operation 4164:Universal 4154:Recursive 4129:Singleton 4124:Inhabited 4109:Countable 4099:Types of 4083:power set 4053:partition 3970:Predicate 3916:Predicate 3831:Syllogism 3821:Soundness 3794:Inference 3784:Tautology 3686:paradoxes 3508:IEEE 1164 3359:Fuzzy set 3230:24 August 2902:Semiotica 2887:0031-8108 2848:0031-8094 2638:0002-9327 2431:Some 3VL 1975:RM3 logic 1863:tautology 1399:, vol 8. 1114:→ 580:OR(A, B) 356:Inside a 135:trivalent 5271:Logicism 5264:timeline 5240:Concrete 5099:Validity 5069:T-schema 5062:Kripke's 5057:Tarski's 5052:semantic 5042:Strength 4991:submodel 4986:spectrum 4954:function 4802:Tarski's 4791:Elements 4778:geometry 4734:Robinson 4655:variable 4640:function 4613:spectrum 4603:Sentence 4559:variable 4502:Language 4455:Relation 4416:Automata 4406:Alphabet 4390:language 4244:-jection 4222:codomain 4208:Function 4169:Universe 4139:Infinite 4043:Relation 3826:Validity 3816:Argument 3714:theorem, 3155:. 42–56. 3060:Archived 3048:Sigma Xi 3011:(1981). 2695:Archived 2587:Archived 2477:See also 2122:HT logic 348:, 1 for 315:, 2 for 167:bivalent 5213:Related 5010:Diagram 4908: ( 4887:Hilbert 4872:Systems 4867:Theorem 4745:of the 4690:systems 4470:Formula 4465:Grammar 4381: ( 4325:General 4038:Forcing 4023:Element 3943:Monadic 3718:paradox 3659:Theorem 3595:General 3501:Verilog 2750:May 15, 2720:May 15, 2691:Commens 2647:2370324 2314:) → ((( 2230:(A, B) 2152:Heyting 1991:(A, B) 1414:(A, B) 1092:unknown 1088:unknown 1076:unknown 1057:unknown 1051:equals 1049:unknown 1043:, then 1027:equals 1017:unknown 1005:unknown 1000:unknown 737:NEG(A) 466:NOT(A) 321:unknown 304:in the 291:, each 287:in the 280:in the 143:trilean 139:ternary 83:scholar 4976:finite 4739:Skolem 4692:  4667:Theory 4635:Symbol 4625:String 4608:atomic 4485:ground 4480:closed 4475:atomic 4431:ground 4394:syntax 4290:binary 4217:domain 4134:Finite 3899:finite 3757:Logics 3716:  3664:Theory 3524:Others 3257:  3221:  3174:  3093:  2885:  2846:  2644:  2636:  2360:coatom 2235:A → B 2146:or as 1996:A → B 1496:A → B 1419:A → B 1291:A → B 1214:A → B 1179:  1157:  1144:  1120:  1031:, and 929:A ⊕ B 856:A ∨ B 783:A ∧ B 658:A ⊕ B 585:A ∨ B 512:A ∧ B 379:Logics 344:0 for 311:1 for 129:(also 85:  78:  71:  64:  56:  4966:Model 4714:Peano 4571:Proof 4411:Arity 4340:Naive 4227:image 4159:Fuzzy 4119:Empty 4068:union 4013:Class 3654:Model 3644:Lemma 3602:Axiom 3341:Fuzzy 3063:(PDF) 3046:(6). 3034:(PDF) 2642:JSTOR 2542:(and 2534:Setun 2148:Gödel 1628:) ∧ ( 1600:= ¬(¬ 1369:(The 1084:false 1072:false 1037:false 1013:false 346:false 337:, or 317:false 295:is a 293:digit 179:false 163:false 141:, or 123:logic 90:JSTOR 76:books 5089:Type 4892:list 4696:list 4673:list 4662:Term 4596:rank 4490:open 4384:list 4196:Maps 4101:sets 3960:Free 3930:list 3680:list 3607:list 3513:VHDL 3255:ISBN 3232:2013 3219:ISBN 3172:ISBN 3091:ISBN 2906:2021 2883:ISSN 2844:ISSN 2752:2023 2722:2023 2634:ISSN 2471:NULL 2326:) → 2322:) → 2179:(A) 2100:) → 1875:and 1604:∨ ¬ 1585:) → 1393:true 1096:true 1090:and 1080:true 1078:and 1061:true 1053:true 1045:true 1041:true 1033:true 1029:true 1025:true 1021:true 1009:true 412:XNOR 396:NAND 350:true 339:both 313:true 298:trit 191:and 177:and 175:true 159:true 125:, a 62:news 4776:of 4758:of 4706:of 4238:Sur 4212:Map 4019:Ur- 4001:Set 3241:doi 3052:doi 2968:doi 2937:doi 2910:doi 2875:doi 2836:doi 2805:doi 2624:hdl 2614:doi 2467:SQL 2455:SQL 2397:. 2341:)∨( 2337:∨(¬ 2291:NF 2271:NF 2246:NF 2226:IMP 2200:NF 2187:¬A 2175:NOT 2144:SmT 2074:→ ( 1989:RM3 1987:IMP 1960:∧ ¬ 1953:∧ ¬ 1936:∨ ¬ 1909:∧ ¬ 1894:∨ ¬ 1695:∧ ¬ 1670:= ¬ 1652:= ¬ 1620:= ( 1577:= ( 1555:+1 1549:−1 1546:+1 1541:+1 1538:+1 1527:+1 1524:+1 1521:+1 1518:−1 1510:+1 1504:−1 1487:IMP 1410:IMP 1350:+1 1344:−1 1341:+1 1336:+1 1322:+1 1319:+1 1316:+1 1313:−1 1305:+1 1299:−1 1282:IMP 1205:IMP 1162:NOT 1047:OR 1035:OR 1023:OR 1011:or 988:−1 982:+1 979:+1 960:+1 954:−1 951:−1 943:+1 937:−1 915:+1 912:+1 909:+1 906:+1 901:+1 887:+1 881:−1 878:−1 870:+1 864:−1 842:+1 836:−1 833:+1 822:−1 814:−1 811:−1 808:−1 805:−1 797:+1 791:−1 769:−1 766:+1 753:+1 750:−1 745:¬A 474:¬A 408:XOR 404:NOR 394:, 392:AND 273:in 147:3VL 121:In 45:by 5321:: 5162:NP 4786:: 4780:: 4710:: 4387:), 4242:Bi 4234:In 3058:. 3044:89 3042:. 3036:. 2974:. 2962:. 2943:. 2933:77 2931:. 2904:. 2881:. 2871:66 2869:. 2865:. 2842:. 2830:. 2826:. 2801:24 2799:. 2785:^ 2769:. 2742:. 2724:. 2712:. 2693:. 2689:. 2664:. 2640:. 2632:. 2622:. 2610:43 2608:. 2604:. 2581:. 2345:→ 2318:→ 2310:→ 2306:(¬ 2294:T 2288:F 2285:T 2280:T 2277:T 2274:F 2266:T 2263:T 2260:T 2257:F 2254:A 2249:T 2243:F 2238:B 2228:HT 2211:F 2208:T 2203:F 2195:T 2192:F 2184:A 2177:HT 2140:HT 2096:⊗ 2082:)) 2078:→ 2055:T 2052:F 2049:F 2046:T 2041:T 2038:U 2035:F 2032:U 2027:T 2024:T 2021:T 2018:F 2015:A 2010:T 2007:U 2004:F 1999:B 1970:). 1949:¬( 1929:∨ 1905:¬( 1903:, 1889:, 1880:↔ 1870:→ 1840:F 1837:T 1832:T 1829:U 1824:F 1821:F 1795:T 1792:T 1787:F 1784:U 1779:F 1776:F 1750:T 1747:T 1742:T 1739:U 1734:F 1731:F 1688:= 1656:→ 1632:→ 1624:→ 1616:⇔ 1596:∧ 1581:→ 1573:∨ 1552:0 1535:0 1532:0 1515:A 1507:0 1499:B 1478:T 1475:U 1472:F 1469:T 1464:T 1461:T 1458:U 1455:U 1450:T 1447:T 1444:T 1441:F 1438:A 1433:T 1430:U 1427:F 1422:B 1347:0 1333:0 1330:0 1327:0 1310:A 1302:0 1294:B 1273:T 1270:U 1267:F 1264:T 1259:T 1256:U 1253:U 1250:U 1245:T 1242:T 1239:T 1236:F 1233:A 1228:T 1225:U 1222:F 1217:B 1149:OR 1074:, 985:0 974:0 971:0 968:0 965:0 957:0 948:A 940:0 932:B 898:0 895:0 892:0 884:0 875:A 867:0 859:B 839:0 828:0 825:0 819:0 802:A 794:0 786:B 761:0 758:0 742:A 717:F 714:U 711:T 708:T 703:U 700:U 697:U 694:U 689:T 686:U 683:F 680:F 677:A 672:T 669:U 666:F 661:B 644:T 641:T 638:T 635:T 630:T 627:U 624:U 621:U 616:T 613:U 610:F 607:F 604:A 599:T 596:U 593:F 588:B 571:T 568:U 565:F 562:T 557:U 554:U 551:F 548:U 543:F 540:F 537:F 534:F 531:A 526:T 523:U 520:F 515:B 498:F 495:T 490:U 487:U 482:T 479:F 471:A 410:, 406:, 402:, 400:OR 398:, 364:. 333:, 323:, 181:. 161:, 137:, 133:, 5242:/ 5157:P 4912:) 4698:) 4694:( 4591:∀ 4586:! 4581:∃ 4542:= 4537:↔ 4532:→ 4527:∧ 4522:∨ 4517:¬ 4240:/ 4236:/ 4210:/ 4021:) 4017:( 3904:∞ 3894:3 3682:) 3580:e 3573:t 3566:v 3287:e 3280:t 3273:v 3243:: 3234:. 3180:. 3099:. 3072:. 3054:: 2970:: 2964:8 2939:: 2916:. 2912:: 2889:. 2877:: 2850:. 2838:: 2832:3 2811:. 2807:: 2779:. 2754:. 2674:. 2650:. 2626:: 2616:: 2556:) 2552:( 2546:) 2404:) 2400:( 2349:) 2347:q 2343:p 2339:q 2335:p 2330:) 2328:p 2324:p 2320:q 2316:p 2312:p 2308:q 2111:U 2102:A 2098:B 2094:A 2092:( 2080:A 2076:B 2072:A 2070:( 1966:( 1964:) 1962:A 1958:A 1955:I 1951:A 1945:) 1941:( 1938:A 1934:A 1931:I 1927:A 1918:I 1913:) 1911:A 1907:A 1896:A 1892:A 1882:A 1878:A 1872:A 1868:A 1814:A 1812:I 1807:A 1769:A 1767:L 1762:A 1724:A 1722:M 1717:A 1700:A 1697:L 1693:A 1690:M 1686:A 1683:I 1676:A 1674:¬ 1672:M 1668:A 1665:L 1658:A 1654:A 1650:A 1647:M 1636:) 1634:A 1630:B 1626:B 1622:A 1618:B 1614:A 1608:) 1606:B 1602:A 1598:B 1594:A 1587:B 1583:B 1579:A 1575:B 1571:A 1489:Ł 1412:Ł 1284:K 1207:K 1185:) 1182:B 1176:, 1173:) 1170:A 1167:( 1154:( 1137:f 1134:e 1131:d 1125:= 1117:B 1111:A 414:( 341:; 327:/ 201:n 112:) 106:( 101:) 97:( 87:· 80:· 73:· 66:· 39:.

Index


verification
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"Three-valued logic"
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logic
many-valued logic
truth values
bivalent
Boolean logic
Emil Leon Post
Jan Łukasiewicz
Clarence Irving Lewis
Grigore Constantin Moisil
Charles Sanders Peirce
many-valued logic system
problem of future contingents
Bruno de Finetti
Hilary Putnam
Stephen Cole Kleene
predicates
ternary numeral system
balanced ternary
redundant binary representation

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