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Truth value

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truth values are sets of programs, which can be understood as computational evidence of validity of a formula. For example, the truth value of the statement "for every number there is a prime larger than it" is the set of all programs that take as input a number
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Even though a Heyting algebra may have many elements, this should not be understood as there being truth values that are neither true nor false, because intuitionistic logic proves
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are treated as false, and strings with content (like "abc"), other numbers, and objects evaluate to true. Sometimes these classes of expressions are called
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exhibits an equivalence of propositions and types, according to which validity is equivalent to inhabitation of a type.
664:. Such truth values may express various aspects of validity, including locality, temporality, or computational content. 120: 2384: 2374: 2111: 1964: 1317: 571: 1308: 3088: 2520: 232: 167: 70: 1862: 2617: 2361: 1186: 127: 1922: 1615: 31: 1356: 886:
are truth-valuational in the sense that logical connectives may be interpreted as truth functions. For example,
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of a topological space as intuitionistic truth values, in which case the truth value of a formula expresses
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But even non-truth-valuational logics can associate values with logical formulae, as is done in
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in the Boolean domain. Assigning values for propositional variables is referred to as
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Proof that intuitionistic logic has no third truth value, Glivenko 1928
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lacks a complete set of truth values because its semantics, the
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may be assigned a truth value in the subobject classifier.
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For other notions of intuitionistic truth values, see the
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Value indicating the relation of a proposition to truth
798: 751: 709: 689: 30:"True and false" redirects here. For other uses, see 924: 864:; this may be expressed as the existence of various 496:, with its intended semantics, the truth values are 785:{\displaystyle \neg (p\neq \top \land p\neq \bot )} 108:. Unsourced material may be challenged and removed. 804: 784: 715: 695: 3065: 574:with respect to negation, which is expressed by 570:true and false. Conjunction and disjunction are 917:semantics of classical propositional calculus. 648:Whereas in classical logic truth values form a 2945: 1187: 898:conditions, and not directly in terms of the 730:, truth values appear as the elements of the 303:can be evaluated in a context that expects a 546:, whose values are expressed in the form of 534:. This set of two values is also called the 71:Learn how and when to remove these messages 2952: 2938: 1379: 1194: 1180: 1152: 1030: 261:, is a value indicating the relation of a 892:Brouwer–Heyting–Kolmogorov interpretation 828:Brouwer–Heyting–Kolmogorov interpretation 675:the formula holds, not whether it holds. 233:Learn how and when to remove this message 168:Learn how and when to remove this message 982:History of logic § Algebraic period 210:of all important aspects of the article. 14: 3066: 1201: 1153:Shramko, Yaroslav; Wansing, Heinrich. 1031:Shramko, Yaroslav; Wansing, Heinrich. 871: 206:Please consider expanding the lead to 2933: 1175: 837: 832:Intuitionistic logic § Semantics 638:Intuitionistic and constructive logic 2959: 179: 106:adding citations to reliable sources 77: 36: 1164:Stanford Encyclopedia of Philosophy 1082:"ECMAScript Language Specification" 1042:Stanford Encyclopedia of Philosophy 299:In some programming languages, any 24: 1119:from the original on 17 March 2011 1113:"The Elements of JavaScript Style" 776: 764: 752: 530:⊥); that is, classical logic is a 403: 384:) to distinguish between strictly 25: 3100: 1146: 703:, and output a prime larger than 394:JavaScript syntax#Type conversion 52:This article has multiple issues. 2996: 2913: 941: 927: 407: 184: 82: 41: 198:may be too short to adequately 93:needs additional citations for 60:or discuss these issues on the 32:True and false (disambiguation) 1131: 1105: 1074: 1049: 1024: 779: 755: 273:has only two possible values ( 208:provide an accessible overview 13: 1: 2874:History of mathematical logic 1017: 812:is neither true nor false"). 667:For example, one may use the 538:. Corresponding semantics of 485:conjunction with disjunction. 2799:Primitive recursive function 1087:. p. 43. Archived from 644:Constructivism (mathematics) 288: 7: 920: 894:, is specified in terms of 821:Curry-Howard correspondence 10: 3105: 1863:Schröder–Bernstein theorem 1590:Monadic predicate calculus 1249:Foundations of mathematics 875: 817:intuitionistic type theory 792:("it is not the case that 660:, the truth values form a 641: 292: 29: 3031: 3005: 2994: 2969: 2909: 2896:Philosophy of mathematics 2845:Automated theorem proving 2827: 2722: 2554: 2447: 2299: 2016: 1992: 1970:Von Neumann–Bernays–Gödel 1915: 1809: 1713: 1611: 1602: 1529: 1464: 1370: 1292: 1209: 479: 415: 3089:Concepts in epistemology 992:Semantic theory of truth 658:constructive mathematics 400:also use this approach. 295:Implicit type conversion 2546:Self-verifying theories 2367:Tarski's axiomatization 1318:Tarski's undefinability 1313:incompleteness theorems 1068:Oxford University Press 624:Propositional variables 2920:Mathematics portal 2531:Proof of impossibility 2179:propositional variable 1489:Propositional calculus 806: 786: 734:. In particular, in a 717: 697: 656:, and more generally, 481:Negation interchanges 2789:Kolmogorov complexity 2742:Computably enumerable 2642:Model complete theory 2434:Principia Mathematica 1494:Propositional formula 1323:Banach–Tarski paradox 1115:. Douglas Crockford. 1064:UK English Dictionary 1007:Truth-value semantics 807: 787: 718: 698: 558:binary relation, and 552:Logical biconditional 372:are sometimes called 257:, sometimes called a 2737:Church–Turing thesis 2724:Computability theory 1933:continuum hypothesis 1451:Square of opposition 1309:Gödel's completeness 962:Bayesian probability 888:intuitionistic logic 860:such structure is a 796: 749: 732:subobject classifier 707: 687: 654:intuitionistic logic 483:true with false and 392:Booleans (see also: 346:, the empty string ( 102:improve this article 2891:Mathematical object 2782:P versus NP problem 2747:Computable function 2541:Reverse mathematics 2467:Logical consequence 2344:primitive recursive 2339:elementary function 2112:Free/bound variable 1965:Tarski–Grothendieck 1484:Logical connectives 1414:Logical equivalence 1264:Logical consequence 907:algebraic semantics 872:Algebraic semantics 843:Multi-valued logics 540:logical connectives 315:, empty lists, and 2689:Transfer principle 2652:Semantics of logic 2637:Categorical theory 2613:Non-standard model 2127:Logical connective 1254:Information theory 1203:Mathematical logic 997:Slingshot argument 967:Circular reasoning 838:Multi-valued logic 802: 782: 740:higher-order logic 713: 693: 327:. For example, in 3074:Concepts in logic 3061: 3060: 2927: 2926: 2859:Abstract category 2662:Theories of truth 2472:Rule of inference 2462:Natural deduction 2443: 2442: 1988: 1987: 1693:Cartesian product 1598: 1597: 1504:Many-valued logic 1479:Boolean functions 1362:Russell's paradox 1337:diagonal argument 1234:First-order logic 1002:Supervaluationism 949:Psychology portal 935:Philosophy portal 805:{\displaystyle p} 738:every formula of 716:{\displaystyle n} 696:{\displaystyle n} 490: 489: 486: 475: 436: 305:Boolean data type 243: 242: 235: 225: 224: 178: 177: 170: 152: 75: 16:(Redirected from 3096: 3000: 2954: 2947: 2940: 2931: 2930: 2918: 2917: 2869:History of logic 2864:Category of sets 2757:Decision problem 2536:Ordinal analysis 2477:Sequent calculus 2375:Boolean algebras 2315: 2314: 2289: 2260:logical/constant 2014: 2013: 2000: 1923:Zermelo–Fraenkel 1674:Set operations: 1609: 1608: 1546: 1377: 1376: 1357:Löwenheim–Skolem 1244:Formal semantics 1196: 1189: 1182: 1173: 1172: 1168: 1159:Zalta, Edward N. 1140: 1135: 1129: 1128: 1126: 1124: 1109: 1103: 1102: 1100: 1099: 1093: 1086: 1078: 1072: 1071: 1053: 1047: 1046: 1037:Zalta, Edward N. 1028: 951: 946: 945: 944: 937: 932: 931: 930: 911:Heyting algebras 866:degrees of truth 859: 811: 809: 808: 803: 791: 789: 788: 783: 722: 720: 719: 714: 702: 700: 699: 694: 619: 618: 614: 610: 606: 599: 598: 594: 590: 586: 576:De Morgan's laws 532:two-valued logic 480: 471: 432: 408: 371: 362: 357: 353: 349: 238: 231: 220: 217: 211: 188: 180: 173: 166: 162: 159: 153: 151: 110: 86: 78: 67: 45: 44: 37: 21: 3104: 3103: 3099: 3098: 3097: 3095: 3094: 3093: 3064: 3063: 3062: 3057: 3027: 3001: 2992: 2965: 2958: 2928: 2923: 2912: 2905: 2850:Category theory 2840:Algebraic logic 2823: 2794:Lambda calculus 2732:Church encoding 2718: 2694:Truth predicate 2550: 2516:Complete theory 2439: 2308: 2304: 2300: 2295: 2287: 2007: and  2003: 1998: 1984: 1960:New Foundations 1928:axiom of choice 1911: 1873:Gödel numbering 1813: and  1805: 1709: 1594: 1544: 1525: 1474:Boolean algebra 1460: 1424:Equiconsistency 1389:Classical logic 1366: 1347:Halting problem 1335: and  1311: and  1299: and  1298: 1293:Theorems ( 1288: 1205: 1200: 1149: 1144: 1143: 1136: 1132: 1122: 1120: 1111: 1110: 1106: 1097: 1095: 1091: 1084: 1080: 1079: 1075: 1055: 1054: 1050: 1029: 1025: 1020: 972:Degree of truth 947: 942: 940: 933: 928: 926: 923: 915:Boolean algebra 900:necessary truth 884:logical systems 880: 878:Algebraic logic 874: 857: 851:relevance logic 840: 797: 794: 793: 750: 747: 746: 728:category theory 708: 705: 704: 688: 685: 684: 662:Heyting algebra 650:Boolean algebra 646: 640: 616: 612: 608: 604: 603: 596: 592: 588: 584: 583: 544:truth functions 494:classical logic 484: 482: 406: 404:Classical logic 369: 360: 355: 351: 347: 297: 291: 271:classical logic 239: 228: 227: 226: 221: 215: 212: 205: 193:This article's 189: 174: 163: 157: 154: 111: 109: 99: 87: 46: 42: 35: 28: 23: 22: 15: 12: 11: 5: 3102: 3092: 3091: 3086: 3081: 3076: 3059: 3058: 3056: 3055: 3050: 3045: 3035: 3033: 3032:Negation  3029: 3028: 3026: 3025: 3020: 3015: 3009: 3007: 3003: 3002: 2995: 2993: 2991: 2990: 2984: 2982:truth function 2979: 2973: 2971: 2967: 2966: 2957: 2956: 2949: 2942: 2934: 2925: 2924: 2910: 2907: 2906: 2904: 2903: 2898: 2893: 2888: 2883: 2882: 2881: 2871: 2866: 2861: 2852: 2847: 2842: 2837: 2835:Abstract logic 2831: 2829: 2825: 2824: 2822: 2821: 2816: 2814:Turing machine 2811: 2806: 2801: 2796: 2791: 2786: 2785: 2784: 2779: 2774: 2769: 2764: 2754: 2752:Computable set 2749: 2744: 2739: 2734: 2728: 2726: 2720: 2719: 2717: 2716: 2711: 2706: 2701: 2696: 2691: 2686: 2681: 2680: 2679: 2674: 2669: 2659: 2654: 2649: 2647:Satisfiability 2644: 2639: 2634: 2633: 2632: 2622: 2621: 2620: 2610: 2609: 2608: 2603: 2598: 2593: 2588: 2578: 2577: 2576: 2571: 2564:Interpretation 2560: 2558: 2552: 2551: 2549: 2548: 2543: 2538: 2533: 2528: 2518: 2513: 2512: 2511: 2510: 2509: 2499: 2494: 2484: 2479: 2474: 2469: 2464: 2459: 2453: 2451: 2445: 2444: 2441: 2440: 2438: 2437: 2429: 2428: 2427: 2426: 2421: 2420: 2419: 2414: 2409: 2389: 2388: 2387: 2385:minimal axioms 2382: 2371: 2370: 2369: 2358: 2357: 2356: 2351: 2346: 2341: 2336: 2331: 2318: 2316: 2297: 2296: 2294: 2293: 2292: 2291: 2279: 2274: 2273: 2272: 2267: 2262: 2257: 2247: 2242: 2237: 2232: 2231: 2230: 2225: 2215: 2214: 2213: 2208: 2203: 2198: 2188: 2183: 2182: 2181: 2176: 2171: 2161: 2160: 2159: 2154: 2149: 2144: 2139: 2134: 2124: 2119: 2114: 2109: 2108: 2107: 2102: 2097: 2092: 2082: 2077: 2075:Formation rule 2072: 2067: 2066: 2065: 2060: 2050: 2049: 2048: 2038: 2033: 2028: 2023: 2017: 2011: 1994:Formal systems 1990: 1989: 1986: 1985: 1983: 1982: 1977: 1972: 1967: 1962: 1957: 1952: 1947: 1942: 1937: 1936: 1935: 1930: 1919: 1917: 1913: 1912: 1910: 1909: 1908: 1907: 1897: 1892: 1891: 1890: 1883:Large cardinal 1880: 1875: 1870: 1865: 1860: 1846: 1845: 1844: 1839: 1834: 1819: 1817: 1807: 1806: 1804: 1803: 1802: 1801: 1796: 1791: 1781: 1776: 1771: 1766: 1761: 1756: 1751: 1746: 1741: 1736: 1731: 1726: 1720: 1718: 1711: 1710: 1708: 1707: 1706: 1705: 1700: 1695: 1690: 1685: 1680: 1672: 1671: 1670: 1665: 1655: 1650: 1648:Extensionality 1645: 1643:Ordinal number 1640: 1630: 1625: 1624: 1623: 1612: 1606: 1600: 1599: 1596: 1595: 1593: 1592: 1587: 1582: 1577: 1572: 1567: 1562: 1561: 1560: 1550: 1549: 1548: 1535: 1533: 1527: 1526: 1524: 1523: 1522: 1521: 1516: 1511: 1501: 1496: 1491: 1486: 1481: 1476: 1470: 1468: 1462: 1461: 1459: 1458: 1453: 1448: 1443: 1438: 1433: 1428: 1427: 1426: 1416: 1411: 1406: 1401: 1396: 1391: 1385: 1383: 1374: 1368: 1367: 1365: 1364: 1359: 1354: 1349: 1344: 1339: 1327:Cantor's  1325: 1320: 1315: 1305: 1303: 1290: 1289: 1287: 1286: 1281: 1276: 1271: 1266: 1261: 1256: 1251: 1246: 1241: 1236: 1231: 1226: 1225: 1224: 1213: 1211: 1207: 1206: 1199: 1198: 1191: 1184: 1176: 1170: 1169: 1155:"Truth Values" 1148: 1147:External links 1145: 1142: 1141: 1130: 1104: 1073: 1048: 1033:"Truth Values" 1022: 1021: 1019: 1016: 1015: 1014: 1012:Verisimilitude 1009: 1004: 999: 994: 989: 984: 979: 974: 969: 964: 959: 953: 952: 938: 922: 919: 913:, compared to 876:Main article: 873: 870: 839: 836: 801: 781: 778: 775: 772: 769: 766: 763: 760: 757: 754: 712: 692: 642:Main article: 639: 636: 621: 620: 600: 536:Boolean domain 488: 487: 477: 476: 469: 466: 463: 462: 455: 452: 449: 448: 445: 442: 438: 437: 430: 427: 424: 423: 416: 414: 411: 405: 402: 376:(of which the 290: 287: 241: 240: 223: 222: 202:the key points 192: 190: 183: 176: 175: 90: 88: 81: 76: 50: 49: 47: 40: 26: 9: 6: 4: 3: 2: 3101: 3090: 3087: 3085: 3084:Logical truth 3082: 3080: 3077: 3075: 3072: 3071: 3069: 3054: 3053:inconsistency 3051: 3049: 3048:contradiction 3046: 3044: 3040: 3037: 3036: 3034: 3030: 3024: 3021: 3019: 3016: 3014: 3011: 3010: 3008: 3004: 2999: 2989: 2986:⊨  2985: 2983: 2980: 2978: 2975: 2974: 2972: 2968: 2963: 2962:Logical truth 2955: 2950: 2948: 2943: 2941: 2936: 2935: 2932: 2922: 2921: 2916: 2908: 2902: 2899: 2897: 2894: 2892: 2889: 2887: 2884: 2880: 2877: 2876: 2875: 2872: 2870: 2867: 2865: 2862: 2860: 2856: 2853: 2851: 2848: 2846: 2843: 2841: 2838: 2836: 2833: 2832: 2830: 2826: 2820: 2817: 2815: 2812: 2810: 2809:Recursive set 2807: 2805: 2802: 2800: 2797: 2795: 2792: 2790: 2787: 2783: 2780: 2778: 2775: 2773: 2770: 2768: 2765: 2763: 2760: 2759: 2758: 2755: 2753: 2750: 2748: 2745: 2743: 2740: 2738: 2735: 2733: 2730: 2729: 2727: 2725: 2721: 2715: 2712: 2710: 2707: 2705: 2702: 2700: 2697: 2695: 2692: 2690: 2687: 2685: 2682: 2678: 2675: 2673: 2670: 2668: 2665: 2664: 2663: 2660: 2658: 2655: 2653: 2650: 2648: 2645: 2643: 2640: 2638: 2635: 2631: 2628: 2627: 2626: 2623: 2619: 2618:of arithmetic 2616: 2615: 2614: 2611: 2607: 2604: 2602: 2599: 2597: 2594: 2592: 2589: 2587: 2584: 2583: 2582: 2579: 2575: 2572: 2570: 2567: 2566: 2565: 2562: 2561: 2559: 2557: 2553: 2547: 2544: 2542: 2539: 2537: 2534: 2532: 2529: 2526: 2525:from ZFC 2522: 2519: 2517: 2514: 2508: 2505: 2504: 2503: 2500: 2498: 2495: 2493: 2490: 2489: 2488: 2485: 2483: 2480: 2478: 2475: 2473: 2470: 2468: 2465: 2463: 2460: 2458: 2455: 2454: 2452: 2450: 2446: 2436: 2435: 2431: 2430: 2425: 2424:non-Euclidean 2422: 2418: 2415: 2413: 2410: 2408: 2407: 2403: 2402: 2400: 2397: 2396: 2394: 2390: 2386: 2383: 2381: 2378: 2377: 2376: 2372: 2368: 2365: 2364: 2363: 2359: 2355: 2352: 2350: 2347: 2345: 2342: 2340: 2337: 2335: 2332: 2330: 2327: 2326: 2324: 2320: 2319: 2317: 2312: 2306: 2301:Example  2298: 2290: 2285: 2284: 2283: 2280: 2278: 2275: 2271: 2268: 2266: 2263: 2261: 2258: 2256: 2253: 2252: 2251: 2248: 2246: 2243: 2241: 2238: 2236: 2233: 2229: 2226: 2224: 2221: 2220: 2219: 2216: 2212: 2209: 2207: 2204: 2202: 2199: 2197: 2194: 2193: 2192: 2189: 2187: 2184: 2180: 2177: 2175: 2172: 2170: 2167: 2166: 2165: 2162: 2158: 2155: 2153: 2150: 2148: 2145: 2143: 2140: 2138: 2135: 2133: 2130: 2129: 2128: 2125: 2123: 2120: 2118: 2115: 2113: 2110: 2106: 2103: 2101: 2098: 2096: 2093: 2091: 2088: 2087: 2086: 2083: 2081: 2078: 2076: 2073: 2071: 2068: 2064: 2061: 2059: 2058:by definition 2056: 2055: 2054: 2051: 2047: 2044: 2043: 2042: 2039: 2037: 2034: 2032: 2029: 2027: 2024: 2022: 2019: 2018: 2015: 2012: 2010: 2006: 2001: 1995: 1991: 1981: 1978: 1976: 1973: 1971: 1968: 1966: 1963: 1961: 1958: 1956: 1953: 1951: 1948: 1946: 1945:Kripke–Platek 1943: 1941: 1938: 1934: 1931: 1929: 1926: 1925: 1924: 1921: 1920: 1918: 1914: 1906: 1903: 1902: 1901: 1898: 1896: 1893: 1889: 1886: 1885: 1884: 1881: 1879: 1876: 1874: 1871: 1869: 1866: 1864: 1861: 1858: 1854: 1850: 1847: 1843: 1840: 1838: 1835: 1833: 1830: 1829: 1828: 1824: 1821: 1820: 1818: 1816: 1812: 1808: 1800: 1797: 1795: 1792: 1790: 1789:constructible 1787: 1786: 1785: 1782: 1780: 1777: 1775: 1772: 1770: 1767: 1765: 1762: 1760: 1757: 1755: 1752: 1750: 1747: 1745: 1742: 1740: 1737: 1735: 1732: 1730: 1727: 1725: 1722: 1721: 1719: 1717: 1712: 1704: 1701: 1699: 1696: 1694: 1691: 1689: 1686: 1684: 1681: 1679: 1676: 1675: 1673: 1669: 1666: 1664: 1661: 1660: 1659: 1656: 1654: 1651: 1649: 1646: 1644: 1641: 1639: 1635: 1631: 1629: 1626: 1622: 1619: 1618: 1617: 1614: 1613: 1610: 1607: 1605: 1601: 1591: 1588: 1586: 1583: 1581: 1578: 1576: 1573: 1571: 1568: 1566: 1563: 1559: 1556: 1555: 1554: 1551: 1547: 1542: 1541: 1540: 1537: 1536: 1534: 1532: 1528: 1520: 1517: 1515: 1512: 1510: 1507: 1506: 1505: 1502: 1500: 1497: 1495: 1492: 1490: 1487: 1485: 1482: 1480: 1477: 1475: 1472: 1471: 1469: 1467: 1466:Propositional 1463: 1457: 1454: 1452: 1449: 1447: 1444: 1442: 1439: 1437: 1434: 1432: 1429: 1425: 1422: 1421: 1420: 1417: 1415: 1412: 1410: 1407: 1405: 1402: 1400: 1397: 1395: 1394:Logical truth 1392: 1390: 1387: 1386: 1384: 1382: 1378: 1375: 1373: 1369: 1363: 1360: 1358: 1355: 1353: 1350: 1348: 1345: 1343: 1340: 1338: 1334: 1330: 1326: 1324: 1321: 1319: 1316: 1314: 1310: 1307: 1306: 1304: 1302: 1296: 1291: 1285: 1282: 1280: 1277: 1275: 1272: 1270: 1267: 1265: 1262: 1260: 1257: 1255: 1252: 1250: 1247: 1245: 1242: 1240: 1237: 1235: 1232: 1230: 1227: 1223: 1220: 1219: 1218: 1215: 1214: 1212: 1208: 1204: 1197: 1192: 1190: 1185: 1183: 1178: 1177: 1174: 1166: 1165: 1160: 1156: 1151: 1150: 1139: 1134: 1118: 1114: 1108: 1094:on 2015-04-12 1090: 1083: 1077: 1069: 1065: 1063: 1058: 1057:"Truth value" 1052: 1044: 1043: 1038: 1034: 1027: 1023: 1013: 1010: 1008: 1005: 1003: 1000: 998: 995: 993: 990: 988: 985: 983: 980: 978: 977:False dilemma 975: 973: 970: 968: 965: 963: 960: 958: 955: 954: 950: 939: 936: 925: 918: 916: 912: 908: 903: 902:of formulae. 901: 897: 893: 889: 885: 879: 869: 867: 863: 858:[0,1] 856: 855:unit interval 852: 848: 844: 835: 833: 829: 824: 822: 818: 813: 799: 773: 770: 767: 761: 758: 743: 741: 737: 733: 729: 724: 710: 690: 681: 680:realizability 676: 674: 670: 665: 663: 659: 655: 651: 645: 635: 633: 629: 625: 601: 581: 580: 579: 577: 573: 569: 565: 561: 557: 553: 549: 545: 541: 537: 533: 529: 525: 521: 520: 515: 514: 509: 505: 501: 500: 495: 478: 474: 470: 467: 465: 464: 460: 456: 453: 451: 450: 446: 443: 440: 439: 435: 431: 428: 426: 425: 421: 417: 412: 410: 409: 401: 399: 395: 391: 387: 383: 379: 375: 367: 363: 345: 340: 338: 334: 330: 326: 322: 318: 314: 310: 306: 302: 296: 286: 284: 283: 278: 277: 272: 268: 264: 260: 259:logical value 256: 252: 248: 237: 234: 219: 209: 203: 201: 196: 191: 187: 182: 181: 172: 169: 161: 158:February 2012 150: 147: 143: 140: 136: 133: 129: 126: 122: 119: –  118: 117:"Truth value" 114: 113:Find sources: 107: 103: 97: 96: 91:This article 89: 85: 80: 79: 74: 72: 65: 64: 59: 58: 53: 48: 39: 38: 33: 19: 18:Logical value 3079:Propositions 3038: 3018:formal proof 2976: 2911: 2709:Ultraproduct 2698: 2556:Model theory 2521:Independence 2457:Formal proof 2449:Proof theory 2432: 2405: 2362:real numbers 2334:second-order 2245:Substitution 2122:Metalanguage 2063:conservative 2036:Axiom schema 1980:Constructive 1950:Morse–Kelley 1916:Set theories 1895:Aleph number 1888:inaccessible 1794:Grothendieck 1678:intersection 1565:Higher-order 1553:Second-order 1499:Truth tables 1456:Venn diagram 1239:Formal proof 1162: 1133: 1121:. Retrieved 1107: 1096:. Retrieved 1089:the original 1076: 1060: 1051: 1040: 1026: 904: 881: 841: 825: 814: 744: 725: 677: 672: 666: 647: 622: 554:becomes the 548:truth tables 523: 522:(denoted by 517: 511: 503: 502:(denoted by 497: 491: 458: 419: 386:type-checked 381: 373: 341: 324: 320: 313:empty string 298: 280: 274: 258: 254: 244: 229: 213: 197: 195:lead section 164: 155: 145: 138: 131: 124: 112: 100:Please help 95:verification 92: 68: 61: 55: 54:Please help 51: 2977:truth value 2970:Functional: 2819:Type theory 2767:undecidable 2699:Truth value 2586:equivalence 2265:non-logical 1878:Enumeration 1868:Isomorphism 1815:cardinality 1799:Von Neumann 1764:Ultrafilter 1729:Uncountable 1663:equivalence 1580:Quantifiers 1570:Fixed-point 1539:First-order 1419:Consistency 1404:Proposition 1381:Traditional 1352:Lindström's 1342:Compactness 1284:Type theory 1229:Cardinality 957:Agnosticism 896:provability 862:total order 847:fuzzy logic 473:disjunction 434:conjunction 269:, which in 263:proposition 255:truth value 251:mathematics 216:August 2021 3068:Categories 2630:elementary 2323:arithmetic 2191:Quantifier 2169:functional 2041:Expression 1759:Transitive 1703:identities 1688:complement 1621:hereditary 1604:Set theory 1098:2011-03-12 1018:References 562:becomes a 378:complement 344:JavaScript 301:expression 293:See also: 128:newspapers 57:improve it 2988:tautology 2901:Supertask 2804:Recursion 2762:decidable 2596:saturated 2574:of models 2497:deductive 2492:axiomatic 2412:Hilbert's 2399:Euclidean 2380:canonical 2303:axiomatic 2235:Signature 2164:Predicate 2053:Extension 1975:Ackermann 1900:Operation 1779:Universal 1769:Recursive 1744:Singleton 1739:Inhabited 1724:Countable 1714:Types of 1698:power set 1668:partition 1585:Predicate 1531:Predicate 1446:Syllogism 1436:Soundness 1409:Inference 1399:Tautology 1301:paradoxes 845:(such as 777:⊥ 774:≠ 768:∧ 765:⊤ 762:≠ 753:¬ 669:open sets 632:valuation 628:variables 564:bijection 356:undefined 289:Computing 200:summarize 63:talk page 2886:Logicism 2879:timeline 2855:Concrete 2714:Validity 2684:T-schema 2677:Kripke's 2672:Tarski's 2667:semantic 2657:Strength 2606:submodel 2601:spectrum 2569:function 2417:Tarski's 2406:Elements 2393:geometry 2349:Robinson 2270:variable 2255:function 2228:spectrum 2218:Sentence 2174:variable 2117:Language 2070:Relation 2031:Automata 2021:Alphabet 2005:language 1859:-jection 1837:codomain 1823:Function 1784:Universe 1754:Infinite 1658:Relation 1441:Validity 1431:Argument 1329:theorem, 1117:Archived 921:See also 882:Not all 568:permutes 560:negation 556:equality 510:⊤), and 3023:theorem 3006:Formal: 2964: ⊤ 2828:Related 2625:Diagram 2523: ( 2502:Hilbert 2487:Systems 2482:Theorem 2360:of the 2305:systems 2085:Formula 2080:Grammar 1996: ( 1940:General 1653:Forcing 1638:Element 1558:Monadic 1333:paradox 1274:Theorem 1210:General 1161:(ed.). 1123:5 March 1039:(ed.). 987:Paradox 626:become 526:or the 506:or the 390:coerced 142:scholar 3041:  3013:theory 2591:finite 2354:Skolem 2307:  2282:Theory 2250:Symbol 2240:String 2223:atomic 2100:ground 2095:closed 2090:atomic 2046:ground 2009:syntax 1905:binary 1832:domain 1749:Finite 1514:finite 1372:Logics 1331:  1279:Theory 1070:. n.d. 1062:Lexico 819:, the 566:which 528:falsum 513:untrue 468:false 382:truthy 364:, +0, 325:truthy 311:, the 144:  137:  130:  123:  115:  3043:false 2581:Model 2329:Peano 2186:Proof 2026:Arity 1955:Naive 1842:image 1774:Fuzzy 1734:Empty 1683:union 1628:Class 1269:Model 1259:Lemma 1217:Axiom 1157:. In 1092:(PDF) 1085:(PDF) 1035:. In 736:topos 673:where 652:, in 611:) ⇔ ¬ 591:) ⇔ ¬ 519:false 508:verum 429:true 374:falsy 370:false 321:falsy 282:false 267:truth 247:logic 149:JSTOR 135:books 2704:Type 2507:list 2311:list 2288:list 2277:Term 2211:rank 2105:open 1999:list 1811:Maps 1716:sets 1575:Free 1545:list 1295:list 1222:list 1125:2011 849:and 830:and 572:dual 542:are 499:true 388:and 368:and 352:null 329:Lisp 323:and 317:null 309:zero 276:true 253:, a 249:and 121:news 2391:of 2373:of 2321:of 1853:Sur 1827:Map 1634:Ur- 1616:Set 815:In 726:In 678:In 615:∧ ¬ 595:∨ ¬ 516:or 492:In 398:PHP 380:is 361:NaN 350:), 342:In 333:nil 285:). 279:or 265:to 245:In 104:by 3070:: 2777:NP 2401:: 2395:: 2325:: 2002:), 1857:Bi 1849:In 1066:. 1059:. 868:. 834:. 723:. 634:. 607:∨ 602:¬( 587:∧ 582:¬( 578:: 550:. 461:· 454:⊥ 447:↕ 444:↕ 441:¬ 422:· 413:⊤ 366:−0 358:, 354:, 348:"" 331:, 66:. 3039:⊥ 2960:‌ 2953:e 2946:t 2939:v 2857:/ 2772:P 2527:) 2313:) 2309:( 2206:∀ 2201:! 2196:∃ 2157:= 2152:↔ 2147:→ 2142:∧ 2137:∨ 2132:¬ 1855:/ 1851:/ 1825:/ 1636:) 1632:( 1519:∞ 1509:3 1297:) 1195:e 1188:t 1181:v 1167:. 1127:. 1101:. 1045:. 800:p 780:) 771:p 759:p 756:( 711:n 691:n 617:q 613:p 609:q 605:p 597:q 593:p 589:q 585:p 524:0 504:1 459:∨ 457:· 420:∧ 418:· 337:C 236:) 230:( 218:) 214:( 204:. 171:) 165:( 160:) 156:( 146:· 139:· 132:· 125:· 98:. 73:) 69:( 34:. 20:)

Index

Logical value
True and false (disambiguation)
improve it
talk page
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verification
improve this article
adding citations to reliable sources
"Truth value"
news
newspapers
books
scholar
JSTOR
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lead section
summarize
provide an accessible overview
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logic
mathematics
proposition
truth
classical logic
true
false
Implicit type conversion
expression

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