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Converse (logic)

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However, the converse of a statement with mutually inclusive terms remains true, given the truth of the original proposition. This is equivalent to saying that the converse of a definition is true. Thus, the statement "If I am a triangle, then I am a three-sided polygon" is logically equivalent to
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proposition "All cats are mammals", the converse "All mammals are cats" is obviously false. However, the weaker statement "Some mammals are cats" is true. Logicians define conversion
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In practice, when determining the converse of a mathematical theorem, aspects of the antecedent may be taken as establishing context. That is, the converse of "Given P, if Q then R
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For example, consider the true statement "If I am a human, then I am mortal." The converse of that statement is "If I am mortal, then I am a human," which is not necessarily
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propositions can be expressed by the restriction that "No term must be distributed in the converse which is not distributed in the convertend." For
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of a categorical or implicational statement is the result of reversing its two constituent statements. For the
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The "exposita" is more usually called the "convertend". In its simple form, conversion is valid only for
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propositions, the subject is distributed while the predicate is not, and so the inference from an
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In traditional logic, the process of switching the subject term with the predicate term is called
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to be the process of producing this weaker statement. Inference from a statement to its converse
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Converse implication is logically equivalent to the disjunction of
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are not logically equivalent, unless both terms imply each other:
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statement to its converse is not valid. As an example, for the
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was proved in 1912, but its converse was proved only in 1997.
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The Science of Logic: or, An Analysis of the Laws of Thought
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is also true), then affirming the consequent will be valid.
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Going from a statement to its converse is the fallacy of
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says nothing about the truth of its converse, unless the
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In mathematics, the converse of a theorem of the form
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Reverse of a categorical or hypothetical proposition
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The World and Language in Wittgenstein's Philosophy
3397: 3360: 3331: 3306: 3277: 3230: 3201: 3172: 3135: 3106: 3077: 3052: 3006: 2853:William Thomas Parry and Edward A. Hacker (1991), 2752:, 2nd ed., Cambridge University Press: "converse". 2654: 2384: 2358: 2304: 2226: 2187: 2149: 2124: 2067: 2045: 2023: 1982: 1925: 1899: 1877: 1855: 1764: 1735: 1704: 1680: 1659: 1637: 1615: 1585: 1562: 1458: 1431: 1404: 1383: 1285:The white area shows where the statement is false. 1275: 1056: 1030: 1004: 970: 944: 903: 861: 835: 809: 783: 749: 726: 699: 676: 645: 610: 584: 543: 517: 491: 459: 424: 398: 372: 331: 305: 279: 245: 219: 193: 159: 130: 104: 81: 55: 1784:In natural language, this could be rendered "not 2598:"Some mammals are unicorns" is clearly false. 2960: 2559:propositions, both subject and predicate are 1181: 8: 2299: 2257: 2003:(Book I, Proposition 48), can be stated as: 2547:The validity of simple conversion only for 2967: 2953: 2945: 2789:"The Four Vertex Theorem and its Converse" 2305:{\displaystyle R^{T}=\{(b,a):(a,b)\in R\}} 1368: 1188: 1174: 18: 3390: 3353: 3324: 3299: 3270: 3223: 3194: 3165: 3128: 3099: 3070: 3045: 2999: 2614: 2410:Categorical proposition § Conversion 2371: 2345: 2248: 2242: 2204: 2180: 2142: 2116: 2103: 2090: 2084: 2060: 2038: 2016: 1974: 1961: 1948: 1942: 1918: 1892: 1870: 1848: 1757: 1728: 1694: 1673: 1652: 1630: 1602: 1575: 1555: 1445: 1418: 1397: 1376: 1262: 1043: 1017: 991: 957: 929: 924: 890: 882: 848: 822: 796: 770: 739: 714: 712: 689: 666: 625: 623: 597: 569: 564: 530: 504: 478: 439: 437: 411: 385: 357: 352: 318: 292: 266: 232: 206: 180: 143: 117: 94: 68: 42: 2456: 1249: 2741: 2171:Converse a simple mathematical relation 1536:and its converse are equivalent (i.e., 1440: 1413: 1124: 1071: 518:{\displaystyle A\not \Leftrightarrow B} 21: 2750:The Cambridge Dictionary of Philosophy 2655:{\displaystyle \forall x.S(x)\to P(x)} 2136:the angle opposite the side of length 1912:the angle opposite the side of length 945:{\displaystyle A{\underline {\lor }}B} 460:{\displaystyle {\overline {A\cdot B}}} 373:{\displaystyle A{\overline {\land }}B} 3202:{\displaystyle \not \leftrightarrow } 2590:is generally valid. However, as with 2227:{\displaystyle R\subseteq A\times B,} 585:{\displaystyle A{\overline {\lor }}B} 246:{\displaystyle A\leftrightharpoons B} 7: 2787:Shonkwiler, Clay (October 6, 2006). 1996:The converse, which also appears in 904:{\displaystyle A\ {\text{XNOR}}\ B} 544:{\displaystyle A\nleftrightarrow B} 3392: 3167: 3001: 2931:. MacMillan, 1979, fifth edition. 2616: 1696: 1577: 1358:A truth table makes it clear that 668: 220:{\displaystyle A\Leftrightarrow B} 151: 148: 122: 14: 2125:{\displaystyle a^{2}+b^{2}=c^{2}} 1983:{\displaystyle a^{2}+b^{2}=c^{2}} 646:{\displaystyle {\overline {A+B}}} 3414: 3231:{\displaystyle \leftrightarrow } 3020: 2684: 2324:The converse of the implication 2010:a triangle with sides of length 1842:a triangle with sides of length 1774: 1746: 1736:{\displaystyle \Leftrightarrow } 1716: 1638:{\displaystyle \Leftrightarrow } 1159: 1158: 727:{\displaystyle {\overline {A}}} 3272: 3225: 3101: 3072: 3047: 2939:A Modern Introduction to Logic 2817:& Thomas Ströhlein (1993) 2649: 2643: 2637: 2634: 2628: 2603:first-order predicate calculus 2418:. For example, going from "No 2350: 2290: 2278: 2272: 2260: 1730: 1632: 1607: 1450: 1432:{\displaystyle P\rightarrow Q} 1423: 1267: 1048: 996: 602: 492:{\displaystyle A\not \equiv B} 390: 332:{\displaystyle A\rightarrow B} 323: 280:{\displaystyle A\Rightarrow B} 271: 237: 211: 160:{\displaystyle A\&\&B} 1: 3307:{\displaystyle \nrightarrow } 2877:, C. Scribner's sons, p. 156. 2359:{\displaystyle P\leftarrow Q} 1827:will be "Given P, if R then Q 1616:{\displaystyle P\leftarrow Q} 1459:{\displaystyle P\leftarrow Q} 1276:{\displaystyle P\leftarrow Q} 1057:{\displaystyle A\leftarrow B} 1005:{\displaystyle A\Leftarrow B} 611:{\displaystyle A\downarrow B} 3332:{\displaystyle \nleftarrow } 3107:{\displaystyle \rightarrow } 1532:. However, if the statement 1326:). In general, the truth of 862:{\displaystyle A\parallel B} 719: 638: 574: 452: 362: 3278:{\displaystyle \downarrow } 3078:{\displaystyle \leftarrow } 1294:be a statement of the form 399:{\displaystyle A\uparrow B} 3461: 2567:propositions, neither is. 2407: 2385:{\displaystyle P\subset Q} 2366:, but may also be notated 1344:are logically equivalent. 1031:{\displaystyle A\subset B} 306:{\displaystyle A\supset B} 3411: 3374: 3254: 3149: 3053:{\displaystyle \uparrow } 3029: 3018: 2983: 2941:. Cromwell Company, 1931. 2748:Robert Audi, ed. (1999), 971:{\displaystyle A\oplus B} 194:{\displaystyle A\equiv B} 2886:Gordon Hunnings (1988), 1530:affirming the consequent 131:{\displaystyle A\&B} 82:{\displaystyle A\cdot B} 56:{\displaystyle A\land B} 3317:Converse nonimplication 1233:categorical proposition 1111:Functional completeness 836:{\displaystyle A\mid B} 784:{\displaystyle A\lor B} 425:{\displaystyle A\mid B} 3399: 3362: 3361:{\displaystyle \land } 3333: 3308: 3279: 3232: 3203: 3174: 3137: 3108: 3079: 3054: 3008: 2656: 2609:can be represented as 2444: 2386: 2360: 2306: 2228: 2189: 2172: 2163:Converse of a relation 2160: 2151: 2126: 2069: 2047: 2025: 1994: 1984: 1927: 1901: 1879: 1857: 1766: 1737: 1706: 1705:{\displaystyle \neg Q} 1682: 1661: 1639: 1617: 1587: 1586:{\displaystyle \neg Q} 1564: 1460: 1433: 1406: 1385: 1287: 1277: 1246:Implicational converse 1081:Propositional calculus 1058: 1032: 1006: 972: 946: 905: 863: 837: 811: 785: 751: 750:{\displaystyle \sim A} 728: 701: 678: 677:{\displaystyle \neg A} 647: 612: 586: 545: 519: 493: 461: 426: 400: 374: 333: 307: 281: 247: 221: 195: 161: 132: 106: 83: 57: 3421:Philosophy portal 3400: 3398:{\displaystyle \bot } 3363: 3334: 3309: 3280: 3233: 3204: 3175: 3173:{\displaystyle \neg } 3138: 3136:{\displaystyle \lor } 3109: 3080: 3055: 3009: 3007:{\displaystyle \top } 2922:Introduction to Logic 2875:The Elements of Logic 2730:Transposition (logic) 2670:cannot be swapped in 2657: 2440: 2387: 2361: 2307: 2229: 2190: 2170: 2152: 2127: 2070: 2048: 2026: 2005: 1985: 1928: 1902: 1880: 1858: 1837: 1796:Converse of a theorem 1767: 1765:{\displaystyle \lor } 1738: 1707: 1683: 1681:{\displaystyle \lor } 1662: 1640: 1618: 1588: 1565: 1461: 1434: 1407: 1386: 1278: 1253: 1139:Programming languages 1059: 1033: 1007: 973: 947: 906: 864: 838: 812: 786: 752: 729: 702: 679: 648: 613: 587: 546: 520: 494: 462: 427: 401: 375: 334: 308: 282: 248: 222: 196: 162: 133: 107: 84: 58: 3389: 3352: 3323: 3298: 3269: 3222: 3193: 3164: 3127: 3098: 3069: 3063:Converse implication 3044: 2998: 2819:Relations and Graphs 2613: 2473:(valid if P exists) 2426:to its converse "No 2404:Categorical converse 2370: 2344: 2241: 2203: 2179: 2141: 2083: 2059: 2037: 2015: 1941: 1917: 1891: 1869: 1847: 1756: 1727: 1693: 1672: 1651: 1629: 1601: 1574: 1554: 1444: 1417: 1396: 1375: 1362:and the converse of 1261: 1042: 1016: 990: 956: 923: 881: 847: 821: 795: 769: 738: 711: 688: 665: 622: 596: 563: 529: 503: 477: 436: 410: 384: 351: 317: 291: 265: 231: 205: 179: 142: 116: 93: 67: 41: 3445:Immediate inference 3440:Logical connectives 2977:logical connectives 2924:. MacMillan, 1953. 2312:is also called the 1833:Pythagorean theorem 1831:. For example, the 1818:four-vertex theorem 1149:Philosophy of logic 810:{\displaystyle A+B} 23:Logical connectives 3395: 3358: 3329: 3304: 3275: 3228: 3199: 3170: 3133: 3104: 3075: 3050: 3034:Alternative denial 3004: 2855:Aristotelian Logic 2796:math.colostate.edu 2762:Taylor, Courtney. 2715:Logical connective 2652: 2434:. In the words of 2398:Bocheński notation 2382: 2356: 2302: 2224: 2185: 2173: 2158:is a right angle. 2147: 2122: 2065: 2043: 2021: 1980: 1934:is a right angle, 1923: 1897: 1875: 1853: 1835:can be stated as: 1762: 1733: 1702: 1678: 1657: 1635: 1613: 1583: 1560: 1456: 1429: 1402: 1381: 1288: 1273: 1238:, the converse is 1223:, the converse is 1144:Mathematical logic 1054: 1028: 1002: 968: 942: 937: 901: 859: 833: 807: 781: 747: 724: 700:{\displaystyle -A} 697: 674: 643: 608: 582: 541: 515: 489: 457: 422: 396: 370: 329: 303: 277: 243: 217: 191: 157: 128: 105:{\displaystyle AB} 102: 79: 53: 3427: 3426: 2692:Philosophy portal 2545: 2544: 2236:converse relation 2188:{\displaystyle R} 2150:{\displaystyle c} 2068:{\displaystyle c} 2046:{\displaystyle b} 2024:{\displaystyle a} 1926:{\displaystyle c} 1900:{\displaystyle c} 1878:{\displaystyle b} 1856:{\displaystyle a} 1782: 1781: 1660:{\displaystyle P} 1563:{\displaystyle P} 1526: 1525: 1405:{\displaystyle Q} 1384:{\displaystyle P} 1314:is the statement 1286: 1198: 1197: 1067: 1066: 930: 897: 893: 889: 722: 641: 577: 455: 365: 3452: 3419: 3418: 3417: 3404: 3402: 3401: 3396: 3367: 3365: 3364: 3359: 3338: 3336: 3335: 3330: 3313: 3311: 3310: 3305: 3284: 3282: 3281: 3276: 3237: 3235: 3234: 3229: 3208: 3206: 3205: 3200: 3179: 3177: 3176: 3171: 3142: 3140: 3139: 3134: 3113: 3111: 3110: 3105: 3084: 3082: 3081: 3076: 3059: 3057: 3056: 3051: 3024: 3013: 3011: 3010: 3005: 2969: 2962: 2955: 2946: 2895: 2884: 2878: 2868: 2862: 2851: 2845: 2831: 2825: 2812: 2806: 2805: 2803: 2802: 2793: 2784: 2778: 2777: 2775: 2774: 2759: 2753: 2746: 2694: 2689: 2688: 2687: 2661: 2659: 2658: 2653: 2507:Some P is not S 2457: 2391: 2389: 2388: 2383: 2365: 2363: 2362: 2357: 2311: 2309: 2308: 2303: 2253: 2252: 2233: 2231: 2230: 2225: 2194: 2192: 2191: 2186: 2156: 2154: 2153: 2148: 2131: 2129: 2128: 2123: 2121: 2120: 2108: 2107: 2095: 2094: 2074: 2072: 2071: 2066: 2052: 2050: 2049: 2044: 2030: 2028: 2027: 2022: 1989: 1987: 1986: 1981: 1979: 1978: 1966: 1965: 1953: 1952: 1932: 1930: 1929: 1924: 1906: 1904: 1903: 1898: 1884: 1882: 1881: 1876: 1862: 1860: 1859: 1854: 1778: 1771: 1769: 1768: 1763: 1750: 1742: 1740: 1739: 1734: 1720: 1711: 1709: 1708: 1703: 1687: 1685: 1684: 1679: 1666: 1664: 1663: 1658: 1644: 1642: 1641: 1636: 1622: 1620: 1619: 1614: 1595: 1594: 1592: 1590: 1589: 1584: 1569: 1567: 1566: 1561: 1465: 1463: 1462: 1457: 1438: 1436: 1435: 1430: 1411: 1409: 1408: 1403: 1390: 1388: 1387: 1382: 1369: 1284: 1282: 1280: 1279: 1274: 1190: 1183: 1176: 1162: 1161: 1106:Boolean function 1072:Related concepts 1063: 1061: 1060: 1055: 1037: 1035: 1034: 1029: 1011: 1009: 1008: 1003: 977: 975: 974: 969: 951: 949: 948: 943: 938: 910: 908: 907: 902: 895: 894: 891: 887: 868: 866: 865: 860: 842: 840: 839: 834: 816: 814: 813: 808: 790: 788: 787: 782: 756: 754: 753: 748: 733: 731: 730: 725: 723: 715: 706: 704: 703: 698: 683: 681: 680: 675: 652: 650: 649: 644: 642: 637: 626: 617: 615: 614: 609: 591: 589: 588: 583: 578: 570: 550: 548: 547: 542: 524: 522: 521: 516: 498: 496: 495: 490: 466: 464: 463: 458: 456: 451: 440: 431: 429: 428: 423: 405: 403: 402: 397: 379: 377: 376: 371: 366: 358: 338: 336: 335: 330: 312: 310: 309: 304: 286: 284: 283: 278: 252: 250: 249: 244: 226: 224: 223: 218: 200: 198: 197: 192: 166: 164: 163: 158: 137: 135: 134: 129: 111: 109: 108: 103: 88: 86: 85: 80: 62: 60: 59: 54: 30: 29: 19: 3460: 3459: 3455: 3454: 3453: 3451: 3450: 3449: 3430: 3429: 3428: 3423: 3415: 3413: 3407: 3387: 3386: 3370: 3350: 3349: 3321: 3320: 3296: 3295: 3267: 3266: 3250: 3220: 3219: 3191: 3190: 3162: 3161: 3145: 3125: 3124: 3096: 3095: 3067: 3066: 3042: 3041: 3025: 3016: 2996: 2995: 2979: 2973: 2935:Stebbing, Susan 2904: 2902:Further reading 2899: 2898: 2885: 2881: 2871:James H. Hyslop 2869: 2865: 2852: 2848: 2832: 2828: 2815:Gunther Schmidt 2813: 2809: 2800: 2798: 2791: 2786: 2785: 2781: 2772: 2770: 2761: 2760: 2756: 2747: 2743: 2738: 2710:Inverse (logic) 2690: 2685: 2683: 2680: 2611: 2610: 2533:Some S is not P 2466:Simple converse 2412: 2406: 2368: 2367: 2342: 2341: 2332:may be written 2322: 2244: 2239: 2238: 2201: 2200: 2197:binary relation 2177: 2176: 2165: 2139: 2138: 2112: 2099: 2086: 2081: 2080: 2057: 2056: 2035: 2034: 2013: 2012: 1970: 1957: 1944: 1939: 1938: 1915: 1914: 1889: 1888: 1867: 1866: 1845: 1844: 1798: 1754: 1753: 1743:   1725: 1724: 1691: 1690: 1670: 1669: 1649: 1648: 1645:   1627: 1626: 1599: 1598: 1572: 1571: 1552: 1551: 1442: 1441: 1415: 1414: 1394: 1393: 1373: 1372: 1283: 1259: 1258: 1248: 1194: 1153: 1120: 1091:Boolean algebra 1086:Predicate logic 1040: 1039: 1014: 1013: 988: 987: 954: 953: 921: 920: 879: 878: 845: 844: 819: 818: 793: 792: 767: 766: 736: 735: 709: 708: 686: 685: 663: 662: 627: 620: 619: 594: 593: 561: 560: 527: 526: 501: 500: 475: 474: 441: 434: 433: 408: 407: 382: 381: 349: 348: 315: 314: 289: 288: 263: 262: 229: 228: 203: 202: 177: 176: 140: 139: 114: 113: 91: 90: 65: 64: 39: 38: 17: 12: 11: 5: 3458: 3456: 3448: 3447: 3442: 3432: 3431: 3425: 3424: 3412: 3409: 3408: 3406: 3405: 3394: 3375: 3372: 3371: 3369: 3368: 3357: 3339: 3328: 3314: 3303: 3288:Nonimplication 3285: 3274: 3255: 3252: 3251: 3249: 3248: 3245:Digital buffer 3238: 3227: 3209: 3198: 3180: 3169: 3150: 3147: 3146: 3144: 3143: 3132: 3114: 3103: 3085: 3074: 3060: 3049: 3030: 3027: 3026: 3019: 3017: 3015: 3014: 3003: 2984: 2981: 2980: 2974: 2972: 2971: 2964: 2957: 2949: 2943: 2942: 2932: 2929:Symbolic Logic 2927:Copi, Irving. 2925: 2915: 2903: 2900: 2897: 2896: 2890:, SUNY Press, 2879: 2863: 2857:, SUNY Press, 2846: 2826: 2823:Springer books 2807: 2779: 2754: 2740: 2739: 2737: 2734: 2733: 2732: 2727: 2722: 2717: 2712: 2707: 2705:Contraposition 2702: 2696: 2695: 2679: 2676: 2651: 2648: 2645: 2642: 2639: 2636: 2633: 2630: 2627: 2624: 2621: 2618: 2543: 2542: 2539: 2534: 2531: 2525: 2524: 2521: 2518: 2515: 2509: 2508: 2505: 2502: 2499: 2493: 2492: 2489: 2484: 2481: 2475: 2474: 2467: 2464: 2461: 2454:propositions: 2405: 2402: 2381: 2378: 2375: 2355: 2352: 2349: 2321: 2318: 2301: 2298: 2295: 2292: 2289: 2286: 2283: 2280: 2277: 2274: 2271: 2268: 2265: 2262: 2259: 2256: 2251: 2247: 2223: 2220: 2217: 2214: 2211: 2208: 2184: 2164: 2161: 2146: 2119: 2115: 2111: 2106: 2102: 2098: 2093: 2089: 2064: 2042: 2020: 1977: 1973: 1969: 1964: 1960: 1956: 1951: 1947: 1922: 1896: 1874: 1852: 1797: 1794: 1780: 1779: 1772: 1761: 1751: 1744: 1732: 1723:   1721: 1713: 1712: 1701: 1698: 1688: 1677: 1667: 1656: 1646: 1634: 1625:   1623: 1612: 1609: 1606: 1582: 1579: 1559: 1542:if and only if 1524: 1523: 1520: 1517: 1514: 1510: 1509: 1506: 1503: 1500: 1496: 1495: 1492: 1489: 1486: 1482: 1481: 1478: 1475: 1472: 1468: 1467: 1455: 1452: 1449: 1439: 1428: 1425: 1422: 1412: 1401: 1391: 1380: 1272: 1269: 1266: 1247: 1244: 1196: 1195: 1193: 1192: 1185: 1178: 1170: 1167: 1166: 1155: 1154: 1152: 1151: 1146: 1141: 1136: 1130: 1127: 1126: 1122: 1121: 1119: 1118: 1113: 1108: 1103: 1101:Truth function 1098: 1093: 1088: 1083: 1077: 1074: 1073: 1069: 1068: 1065: 1064: 1053: 1050: 1047: 1027: 1024: 1021: 1001: 998: 995: 985: 979: 978: 967: 964: 961: 941: 936: 933: 928: 918: 912: 911: 900: 886: 876: 870: 869: 858: 855: 852: 832: 829: 826: 806: 803: 800: 780: 777: 774: 764: 758: 757: 746: 743: 721: 718: 696: 693: 673: 670: 660: 654: 653: 640: 636: 633: 630: 607: 604: 601: 581: 576: 573: 568: 558: 552: 551: 540: 537: 534: 514: 511: 508: 488: 485: 482: 472: 468: 467: 454: 450: 447: 444: 421: 418: 415: 395: 392: 389: 369: 364: 361: 356: 346: 340: 339: 328: 325: 322: 302: 299: 296: 276: 273: 270: 260: 254: 253: 242: 239: 236: 216: 213: 210: 190: 187: 184: 174: 168: 167: 156: 153: 150: 147: 127: 124: 121: 101: 98: 78: 75: 72: 52: 49: 46: 36: 26: 25: 15: 13: 10: 9: 6: 4: 3: 2: 3457: 3446: 3443: 3441: 3438: 3437: 3435: 3422: 3410: 3384: 3380: 3379:Contradiction 3377: 3376: 3373: 3355: 3347: 3343: 3340: 3326: 3318: 3315: 3301: 3293: 3289: 3286: 3264: 3260: 3257: 3256: 3253: 3246: 3242: 3239: 3217: 3213: 3212:Biconditional 3210: 3196: 3188: 3184: 3181: 3159: 3155: 3152: 3151: 3148: 3130: 3122: 3118: 3115: 3093: 3089: 3086: 3064: 3061: 3039: 3035: 3032: 3031: 3028: 3023: 2993: 2989: 2986: 2985: 2982: 2978: 2970: 2965: 2963: 2958: 2956: 2951: 2950: 2947: 2940: 2936: 2933: 2930: 2926: 2923: 2919: 2916: 2913: 2909: 2906: 2905: 2901: 2893: 2889: 2883: 2880: 2876: 2872: 2867: 2864: 2860: 2856: 2850: 2847: 2843: 2839: 2835: 2830: 2827: 2824: 2820: 2816: 2811: 2808: 2797: 2790: 2783: 2780: 2769: 2765: 2758: 2755: 2751: 2745: 2742: 2735: 2731: 2728: 2726: 2723: 2721: 2718: 2716: 2713: 2711: 2708: 2706: 2703: 2701: 2698: 2697: 2693: 2682: 2677: 2675: 2673: 2669: 2665: 2646: 2640: 2631: 2625: 2622: 2619: 2608: 2604: 2599: 2597: 2593: 2589: 2585: 2581: 2577: 2573: 2568: 2566: 2562: 2558: 2554: 2550: 2540: 2538: 2535: 2532: 2530: 2527: 2526: 2522: 2519: 2516: 2514: 2511: 2510: 2506: 2503: 2500: 2498: 2495: 2494: 2490: 2488: 2485: 2482: 2480: 2477: 2476: 2472: 2468: 2465: 2462: 2459: 2458: 2455: 2453: 2449: 2443: 2439: 2437: 2433: 2429: 2425: 2421: 2417: 2411: 2403: 2401: 2399: 2395: 2379: 2376: 2373: 2353: 2347: 2339: 2335: 2331: 2327: 2319: 2317: 2315: 2296: 2293: 2287: 2284: 2281: 2275: 2269: 2266: 2263: 2254: 2249: 2245: 2237: 2221: 2218: 2215: 2212: 2209: 2206: 2198: 2182: 2169: 2162: 2159: 2157: 2144: 2135: 2117: 2113: 2109: 2104: 2100: 2096: 2091: 2087: 2079: 2075: 2062: 2053: 2040: 2031: 2018: 2009: 2004: 2002: 2001: 1993: 1992: 1975: 1971: 1967: 1962: 1958: 1954: 1949: 1945: 1937: 1933: 1920: 1911: 1907: 1894: 1885: 1872: 1863: 1850: 1841: 1836: 1834: 1830: 1826: 1821: 1819: 1815: 1811: 1807: 1803: 1795: 1793: 1791: 1787: 1777: 1773: 1759: 1752: 1749: 1745: 1722: 1719: 1715: 1714: 1699: 1689: 1675: 1668: 1654: 1647: 1624: 1610: 1604: 1597: 1596: 1593: 1580: 1557: 1548: 1546: 1543: 1539: 1535: 1531: 1521: 1518: 1515: 1512: 1511: 1507: 1504: 1501: 1498: 1497: 1493: 1490: 1487: 1484: 1483: 1479: 1476: 1473: 1470: 1469: 1453: 1447: 1426: 1420: 1399: 1392: 1378: 1371: 1370: 1367: 1365: 1361: 1356: 1352: 1350: 1345: 1343: 1340: 1336: 1333: 1329: 1325: 1321: 1317: 1313: 1309: 1305: 1301: 1297: 1293: 1270: 1264: 1256: 1252: 1245: 1243: 1241: 1237: 1234: 1230: 1226: 1222: 1218: 1215: 1211: 1207: 1203: 1191: 1186: 1184: 1179: 1177: 1172: 1171: 1169: 1168: 1165: 1157: 1156: 1150: 1147: 1145: 1142: 1140: 1137: 1135: 1134:Digital logic 1132: 1131: 1129: 1128: 1123: 1117: 1116:Scope (logic) 1114: 1112: 1109: 1107: 1104: 1102: 1099: 1097: 1094: 1092: 1089: 1087: 1084: 1082: 1079: 1078: 1076: 1075: 1070: 1051: 1045: 1025: 1022: 1019: 999: 993: 986: 984: 981: 980: 965: 962: 959: 939: 934: 931: 926: 919: 917: 914: 913: 898: 884: 877: 875: 872: 871: 856: 853: 850: 830: 827: 824: 804: 801: 798: 778: 775: 772: 765: 763: 760: 759: 744: 741: 716: 694: 691: 671: 661: 659: 656: 655: 634: 631: 628: 605: 599: 579: 571: 566: 559: 557: 554: 553: 538: 535: 532: 512: 509: 506: 486: 483: 480: 473: 471:nonequivalent 470: 469: 448: 445: 442: 419: 416: 413: 393: 387: 367: 359: 354: 347: 345: 342: 341: 326: 320: 300: 297: 294: 274: 268: 261: 259: 256: 255: 240: 234: 214: 208: 188: 185: 182: 175: 173: 170: 169: 154: 145: 125: 119: 99: 96: 76: 73: 70: 50: 47: 44: 37: 35: 32: 31: 28: 27: 24: 20: 3259:Joint denial 3183:Exclusive or 3062: 2938: 2928: 2921: 2918:Copi, Irving 2911: 2887: 2882: 2874: 2866: 2854: 2849: 2837: 2829: 2818: 2810: 2799:. Retrieved 2795: 2782: 2771:. Retrieved 2767: 2757: 2749: 2744: 2671: 2667: 2663: 2606: 2600: 2596:per accidens 2595: 2588:per accidens 2587: 2584:per accidens 2583: 2579: 2575: 2571: 2569: 2564: 2563:, while for 2556: 2552: 2548: 2546: 2536: 2528: 2512: 2496: 2491:Some P is S 2486: 2478: 2471:per accidens 2470: 2451: 2447: 2445: 2441: 2431: 2427: 2423: 2419: 2415: 2413: 2393: 2337: 2333: 2329: 2325: 2323: 2313: 2174: 2137: 2133: 2077: 2055: 2033: 2011: 2007: 2006: 1999: 1995: 1990: 1935: 1913: 1909: 1887: 1865: 1843: 1839: 1838: 1828: 1824: 1822: 1813: 1809: 1805: 1801: 1799: 1789: 1785: 1783: 1549: 1544: 1537: 1533: 1527: 1363: 1359: 1357: 1353: 1346: 1341: 1334: 1327: 1323: 1319: 1315: 1311: 1307: 1306:). Then the 1303: 1299: 1295: 1291: 1289: 1255:Venn diagram 1239: 1235: 1228: 1224: 1220: 1216: 1209: 1199: 1125:Applications 982: 3342:Conjunction 3292:NIMPLY gate 3117:Disjunction 3088:Implication 2672:All S are P 2607:All S are P 2561:distributed 2520:Some P is S 2517:Some S is P 2483:All S are P 1316:Q implies P 1296:P implies Q 1240:All P are S 1236:All S are P 1214:implication 1206:mathematics 1096:Truth table 3434:Categories 3092:IMPLY gate 2821:, page 9, 2801:2019-11-26 2773:2019-11-27 2736:References 2725:Term logic 2592:syllogisms 2463:Convertend 2416:conversion 2408:See also: 1466:(converse) 1339:consequent 1332:antecedent 1231:. For the 172:equivalent 3393:⊥ 3356:∧ 3327:↚ 3302:↛ 3273:↓ 3241:Statement 3226:↔ 3216:XNOR gate 3168:¬ 3131:∨ 3102:→ 3073:← 3048:↑ 3038:NAND gate 3002:⊤ 2988:Tautology 2908:Aristotle 2834:Asa Mahan 2768:ThoughtCo 2720:Obversion 2700:Aristotle 2638:→ 2617:∀ 2537:not valid 2504:No P is S 2501:No S is P 2487:not valid 2469:Converse 2436:Asa Mahan 2377:⊂ 2351:← 2314:transpose 2294:∈ 2234:then the 2216:× 2210:⊆ 1998:Euclid's 1760:∨ 1731:⇔ 1697:¬ 1676:∨ 1633:⇔ 1608:← 1578:¬ 1451:← 1424:→ 1268:← 1049:← 1023:⊂ 997:⇐ 963:⊕ 935:_ 932:∨ 854:∥ 828:∣ 776:∨ 742:∼ 720:¯ 692:− 669:¬ 639:¯ 603:↓ 575:¯ 572:∨ 536:↮ 453:¯ 446:⋅ 417:∣ 391:↑ 363:¯ 360:∧ 324:→ 298:⊃ 272:⇒ 238:⇋ 212:⇔ 186:≡ 152:& 149:& 123:& 74:⋅ 48:∧ 3346:AND gate 3263:NOR gate 3197:↮ 3187:XOR gate 3158:NOT gate 3154:Negation 2873:(1892), 2678:See also 2320:Notation 2000:Elements 1808:will be 1788:without 1540:is true 1337:and the 1308:converse 1210:converse 1164:Category 983:converse 510:⇎ 484:≢ 3348:)  3344: ( 3294:)  3290: ( 3265:)  3261: ( 3243: ( 3218:)  3214: ( 3189:)  3185: ( 3160:)  3156: ( 3123:)  3121:OR gate 3119: ( 3094:)  3090: ( 3040:)  3036: ( 2975:Common 2912:Organon 2836:(1857) 2392:, or "B 258:implies 3385:  3319:  3065:  2994:  2859:p. 207 2396:" (in 2054:, and 1886:, and 1208:, the 896:  888:  3383:False 2892:p. 42 2842:p. 82 2792:(PDF) 2199:with 2195:is a 2008:Given 1840:Given 1202:logic 2992:True 2666:and 2570:For 2551:and 2460:Type 2450:and 2430:are 2422:are 2134:then 1936:then 1570:and 1349:true 1290:Let 1204:and 892:XNOR 874:XNOR 344:NAND 2601:In 2400:). 2175:If 1792:". 1310:of 1257:of 1200:In 916:XOR 658:NOT 556:NOR 34:AND 3436:: 2937:. 2920:. 2910:. 2840:, 2794:. 2766:. 2674:. 2605:, 2541:– 2523:– 2438:: 2432:S" 2424:P" 2394:pq 2340:, 2336:→ 2328:→ 2316:. 2132:, 2078:if 2076:, 2032:, 1910:if 1908:, 1864:, 1812:→ 1804:→ 1351:. 1322:→ 1302:→ 1227:→ 1219:→ 1038:, 1012:, 952:, 843:, 817:, 791:, 762:OR 734:, 707:, 684:, 618:, 592:, 525:, 499:, 432:, 406:, 380:, 313:, 287:, 227:, 201:, 138:, 112:, 89:, 63:, 3381:/ 3247:) 2990:/ 2968:e 2961:t 2954:v 2914:. 2894:. 2861:. 2844:. 2804:. 2776:. 2668:P 2664:S 2650:) 2647:x 2644:( 2641:P 2635:) 2632:x 2629:( 2626:S 2623:. 2620:x 2580:A 2576:A 2572:A 2565:I 2557:E 2553:I 2549:E 2529:O 2513:I 2497:E 2479:A 2452:I 2448:E 2428:P 2420:S 2380:Q 2374:P 2354:Q 2348:P 2338:P 2334:Q 2330:Q 2326:P 2300:} 2297:R 2291:) 2288:b 2285:, 2282:a 2279:( 2276:: 2273:) 2270:a 2267:, 2264:b 2261:( 2258:{ 2255:= 2250:T 2246:R 2222:, 2219:B 2213:A 2207:R 2183:R 2145:c 2118:2 2114:c 2110:= 2105:2 2101:b 2097:+ 2092:2 2088:a 2063:c 2041:b 2019:a 1991:. 1976:2 1972:c 1968:= 1963:2 1959:b 1955:+ 1950:2 1946:a 1921:c 1895:c 1873:b 1851:a 1829:" 1825:" 1814:P 1810:Q 1806:Q 1802:P 1790:P 1786:Q 1700:Q 1655:P 1611:Q 1605:P 1581:Q 1558:P 1545:Q 1538:P 1534:S 1522:T 1519:T 1516:T 1513:T 1508:T 1505:F 1502:F 1499:T 1494:F 1491:T 1488:T 1485:F 1480:T 1477:T 1474:F 1471:F 1454:Q 1448:P 1427:Q 1421:P 1400:Q 1379:P 1364:S 1360:S 1342:Q 1335:P 1328:S 1324:P 1320:Q 1318:( 1312:S 1304:Q 1300:P 1298:( 1292:S 1271:Q 1265:P 1229:P 1225:Q 1221:Q 1217:P 1189:e 1182:t 1175:v 1052:B 1046:A 1026:B 1020:A 1000:B 994:A 966:B 960:A 940:B 927:A 899:B 885:A 857:B 851:A 831:B 825:A 805:B 802:+ 799:A 779:B 773:A 745:A 717:A 695:A 672:A 635:B 632:+ 629:A 606:B 600:A 580:B 567:A 539:B 533:A 513:B 507:A 487:B 481:A 449:B 443:A 420:B 414:A 394:B 388:A 368:B 355:A 327:B 321:A 301:B 295:A 275:B 269:A 241:B 235:A 215:B 209:A 189:B 183:A 155:B 146:A 126:B 120:A 100:B 97:A 77:B 71:A 51:B 45:A

Index

Logical connectives
AND
equivalent
implies
NAND
NOR
NOT
OR
XNOR
XOR
converse
Propositional calculus
Predicate logic
Boolean algebra
Truth table
Truth function
Boolean function
Functional completeness
Scope (logic)
Digital logic
Programming languages
Mathematical logic
Philosophy of logic
Category
v
t
e
logic
mathematics
implication

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