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General frame

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Validity and other concepts are then introduced similarly to modal frames, with a few changes necessary to accommodate for the weaker closure properties of the set of admissible valuations. In particular, an intuitionistic frame
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Descriptive frames are the most important class of frames because of the duality theory (see below). Refined frames are useful as a common generalization of descriptive and Kripke frames.
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are a pair of contravariant functors, which make the category of Heyting algebras dually equivalent to the category of descriptive intuitionistic frames.
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Kripke frames are refined and atomic. However, infinite Kripke frames are never compact. Every finite differentiated or atomic frame is a Kripke frame.
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A frame and its dual validate the same formulas; hence the general frame semantics and algebraic semantics are in a sense equivalent. The double dual
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It is also possible to define duals of p-morphisms on one hand, and modal algebra homomorphisms on the other hand. In this way the operators
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The frame semantics for intuitionistic and intermediate logics can be developed in parallel to the semantics for modal logics. An
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itself. This is not true in general for double duals of frames, as the dual of every algebra is descriptive. In fact, a frame
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It is possible to construct intuitionistic general frames from transitive reflexive modal frames and vice versa, see
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is complete with respect to its canonical model, and the general frame induced by the canonical model (called the
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Its dual Heyting algebra, the Rieger–Nishimura lattice. It is the free Heyting algebra over 1 generator.
2033: 1237: 3885: 3625: 279:: it shares the transparent geometrical insight of the former, and robust completeness of the latter. 5244: 2828: 5158: 5125: 4960: 4247: 4214: 4147: 4125: 3843: 3603: 1105: 1083: 1037: 920: 683: 2913: 2281: 1012: 462: 268: 41: 5231:, vol. 53 of Cambridge Tracts in Theoretical Computer Science, Cambridge University Press, 2001. 942: 4294: 3160:
is complete with respect to a class of general frames. This is a consequence of the fact that
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may be identified with a general frame in which all valuations are admissible: i.e.,
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of general frames, and the category of modal algebras. These functors provide a
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In full generality, general frames are hardly more than a fancy name for Kripke
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Tight intuitionistic frames are automatically differentiated, hence refined.
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The Rieger–Nishimura ladder: a 1-universal intuitionistic Kripke frame.
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The fundamental truth-preserving operations of generated subframes,
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with the finite intersection property has a non-empty intersection.
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is descriptive if and only if it is isomorphic to its double dual
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logics. The general frame semantics combines the main virtues of
5220:, vol. 35 of Oxford Logic Guides, Oxford University Press, 1997. 3519:{\displaystyle \langle {\mathcal {P}}(F),\cap ,\cup ,-\rangle } 1501:{\displaystyle \forall A\in V\,(x\in \Box A\Rightarrow y\in A)} 4612:{\displaystyle \forall A\in V\,(x\in A\Leftrightarrow y\in A)} 1409:{\displaystyle \forall A\in V\,(x\in A\Leftrightarrow y\in A)} 158: 56: 15: 4303:
complex algebras and fields of sets on relational structures
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is to restrict the allowed valuations in the frame: a model
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In the opposite direction, it is possible to construct the
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is closed under substitution, the general frame induced by
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is closed under Boolean operations, therefore it is a
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with an additional structure, which are used to model
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is complete with respect to a class of Kripke models
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Unsourced material may be challenged and removed. 5180: 5147: 5114: 5085: 5035: 5015: 4991: 4971: 4945: 4925: 4872: 4814: 4746: 4693: 4637: 4611: 4547: 4496: 4439: 4411: 4391: 4367: 4347: 4269: 4236: 4200: 4158: 4136: 4114: 4069: 4049: 4026: 3947: 3927: 3903: 3874: 3854: 3828: 3804: 3760: 3702: 3643: 3614: 3588: 3538: 3518: 3454: 3435:{\displaystyle \mathbf {F} =\langle F,R,V\rangle } 3434: 3360: 3336: 3312: 3292: 3272: 3232: 3212: 3172: 3152: 3124: 3070: 2958: 2938: 2899: 2820:{\displaystyle \mathbf {G} =\langle G,S,W\rangle } 2819: 2774:{\displaystyle \mathbf {F} =\langle F,R,V\rangle } 2773: 2720: 2625: 2580: 2560: 2515: 2496:{\displaystyle \mathbf {F} =\langle F,R,V\rangle } 2495: 2449: 2423: 2341: 2315: 2267: 2235: 2203: 2183: 2163: 2116: 2060: 2022: 2002: 1982: 1962: 1930: 1899:{\displaystyle \mathbf {F} =\langle F,R,V\rangle } 1898: 1849:{\displaystyle \mathbf {G} =\langle G,S,W\rangle } 1848: 1795: 1712: 1692: 1651: 1584: 1554: 1528: 1500: 1434: 1408: 1345:{\displaystyle \mathbf {F} =\langle F,R,V\rangle } 1344: 1283: 1259: 1226: 1175: 1136: 1116: 1094: 1072: 1048: 1026: 1003: 977: 957: 931: 905: 882: 858: 838: 794: 770: 747: 694: 668: 636: 598: 570: 484: 445: 425: 405: 381: 361: 330:{\displaystyle \mathbf {F} =\langle F,R,V\rangle } 329: 4447:that contains the empty set, and is closed under 3805:{\displaystyle \langle A,\wedge ,\vee ,-\rangle } 3526:. It also carries an additional unary operation, 186:but its sources remain unclear because it lacks 3140:Unlike Kripke frames, every normal modal logic 5216:Alexander Chagrov and Michael Zakharyaschev, 3273:{\displaystyle \langle F,R,{\Vdash }\rangle } 3213:{\displaystyle \langle F,R,{\Vdash }\rangle } 1785: 1738: 1652:{\displaystyle \langle F,R,{\Vdash }\rangle } 748:{\displaystyle \{x\in F\mid x\Vdash p\}\in V} 8: 5077: 5053: 4920: 4902: 4867: 4837: 4809: 4779: 4741: 4723: 4688: 4664: 4542: 4524: 4342: 4324: 3799: 3775: 3755: 3725: 3697: 3679: 3583: 3553: 3513: 3476: 3429: 3411: 3267: 3247: 3207: 3187: 3008: 2976: 2814: 2796: 2768: 2750: 2712: 2649: 2620: 2595: 2555: 2530: 2490: 2472: 2418: 2379: 2262: 2250: 2230: 2218: 2108: 2084: 1957: 1945: 1938:is a generated subframe of the Kripke frame 1925: 1913: 1893: 1875: 1843: 1825: 1767: 1743: 1687: 1669: 1646: 1626: 1339: 1321: 1221: 1190: 1170: 1158: 833: 809: 736: 712: 663: 651: 631: 613: 565: 508: 356: 344: 324: 306: 637:{\displaystyle \langle F,R,\Vdash \rangle } 50:Learn how and when to remove these messages 3980: 3976: 3125:{\displaystyle A/{\sim }\in W\iff A\in V.} 3109: 3105: 3021: 3017: 2853: 2849: 2275:, and satisfies the additional constraint 2211:that is a p-morphism of the Kripke frames 5172: 5160: 5139: 5127: 5101: 5051: 5028: 5008: 4984: 4964: 4962: 4938: 4893: 4888: 4885: 4829: 4827: 4770: 4765: 4762: 4715: 4713: 4656: 4624: 4581: 4567: 4516: 4514: 4459: 4432: 4404: 4384: 4360: 4348:{\displaystyle \langle F,\leq ,V\rangle } 4322: 4261: 4249: 4228: 4216: 4192: 4182: 4177: 4171: 4151: 4149: 4129: 4127: 4106: 4096: 4091: 4085: 4062: 4042: 3993: 3972: 3968: 3963: 3940: 3920: 3895: 3890: 3887: 3867: 3847: 3845: 3821: 3773: 3717: 3715: 3670: 3665: 3662: 3635: 3630: 3627: 3607: 3605: 3551: 3531: 3480: 3479: 3474: 3447: 3403: 3401: 3353: 3329: 3305: 3285: 3262: 3245: 3225: 3202: 3185: 3165: 3145: 3094: 3089: 3084: 3034: 3003: 2998: 2987: 2982: 2974: 2951: 2931: 2926: 2915: 2866: 2838: 2788: 2786: 2742: 2740: 2703: 2690: 2676: 2641: 2602: 2593: 2573: 2537: 2528: 2508: 2464: 2462: 2436: 2412: 2399: 2386: 2370: 2365: 2362: 2328: 2289: 2283: 2248: 2216: 2196: 2176: 2156: 2148: 2140: 2117:{\displaystyle W=\{A\cap G\mid A\in V\}.} 2076: 2035: 2015: 1995: 1975: 1943: 1911: 1867: 1865: 1817: 1815: 1784: 1783: 1776: 1737: 1736: 1728: 1705: 1667: 1641: 1624: 1577: 1547: 1522: 1518: 1513: 1467: 1453: 1421: 1378: 1364: 1313: 1311: 1276: 1242: 1241: 1239: 1206: 1205: 1188: 1156: 1129: 1109: 1107: 1087: 1085: 1065: 1041: 1039: 1019: 990: 970: 944: 924: 922: 898: 875: 851: 807: 787: 763: 710: 687: 685: 649: 611: 591: 546: 542: 535: 497: 477: 438: 418: 398: 374: 342: 298: 296: 235:Learn how and when to remove this message 217:Learn how and when to remove this message 147:Learn how and when to remove this message 4694:{\displaystyle V\cup \{F-A\mid A\in V\}} 3596:is a modal algebra, which is called the 3392:General frames bear close connection to 839:{\displaystyle \{x\in F\mid x\Vdash A\}} 584:fields of sets with additional structure 5086:{\displaystyle \{x\in F\mid a\in x\},} 4497:{\displaystyle A\to B=\Box (-A\cup B)} 4201:{\displaystyle (\mathbf {F} ^{+})_{+}} 4122:of any modal algebra is isomorphic to 4115:{\displaystyle (\mathbf {A} _{+})^{+}} 1056:, if all axioms (or equivalently, all 3320:is complete with respect to a single 2946:be the set of equivalence classes of 1693:{\displaystyle \langle F,R,V\rangle } 7: 4708:The dual of an intuitionistic frame 2827:defined as follows. We consider the 2626:{\displaystyle \{R_{i}\mid i\in I\}} 2561:{\displaystyle \{F_{i}\mid i\in I\}} 1598:, if it is differentiated and tight, 453:that is closed under the following: 85:adding citations to reliable sources 2268:{\displaystyle \langle G,S\rangle } 2236:{\displaystyle \langle F,R\rangle } 1963:{\displaystyle \langle F,R\rangle } 1931:{\displaystyle \langle G,S\rangle } 1176:{\displaystyle \langle F,R\rangle } 669:{\displaystyle \langle F,R\rangle } 457:the Boolean operations of (binary) 362:{\displaystyle \langle F,R\rangle } 4806: 4569: 3981: 3022: 2854: 2664: 1615:Operations and morphisms on frames 1455: 1366: 523: 14: 3935:, and the accessibility relation 2061:{\displaystyle S=R\cap G\times G} 1260:{\displaystyle {\mathcal {P}}(F)} 31:This article has multiple issues. 4965: 4889: 4830: 4822:. The dual of a Heyting algebra 4766: 4716: 4517: 4178: 4152: 4130: 4092: 3904:{\displaystyle \mathbf {A} _{+}} 3891: 3848: 3718: 3666: 3644:{\displaystyle \mathbf {F} ^{+}} 3631: 3608: 3404: 2789: 2743: 2465: 2366: 2157: 2149: 1868: 1818: 1314: 1110: 1088: 1042: 925: 688: 582:They are thus a special case of 299: 163: 61: 20: 1604:, if it is refined and compact. 72:needs additional citations for 39:or discuss these issues on the 5169: 5162: 5136: 5129: 4858: 4800: 4606: 4594: 4582: 4491: 4476: 4464: 4258: 4251: 4225: 4218: 4189: 4173: 4103: 4087: 4021: 4009: 3994: 3977: 3492: 3486: 3300:-frame. Moreover, every logic 3106: 3062: 3050: 3035: 3018: 2891: 2879: 2867: 2850: 2709: 2677: 2304: 2298: 2153: 1495: 1483: 1468: 1403: 1391: 1379: 1254: 1248: 1218: 1212: 965:for all admissible valuations 562: 550: 536: 1: 1566:has a non-empty intersection, 5181:{\displaystyle (\cdot )_{+}} 5148:{\displaystyle (\cdot )^{+}} 4972:{\displaystyle \mathbf {A} } 4880:is the intuitionistic frame 4315:intuitionistic general frame 4270:{\displaystyle (\cdot )_{+}} 4237:{\displaystyle (\cdot )^{+}} 4159:{\displaystyle \mathbf {F} } 4137:{\displaystyle \mathbf {A} } 3882:of admissible valuations in 3855:{\displaystyle \mathbf {A} } 3615:{\displaystyle \mathbf {F} } 3442:be a general frame. The set 2357:of an indexed set of frames 1564:finite intersection property 1117:{\displaystyle \mathbf {F} } 1095:{\displaystyle \mathbf {F} } 1049:{\displaystyle \mathbf {F} } 932:{\displaystyle \mathbf {F} } 695:{\displaystyle \mathbf {F} } 5023:consists of all subsets of 2939:{\displaystyle G=F/{\sim }} 2316:{\displaystyle f^{-1}\in V} 5276: 782:The closure conditions on 644:based on the Kripke frame 3546:. The combined structure 2523:is the disjoint union of 958:{\displaystyle x\Vdash A} 369:is a Kripke frame (i.e., 5122:. As in the modal case, 1592:contains all singletons, 172:This article includes a 4638:{\displaystyle x\leq y} 4451:intersection and union, 3816:, whose underlying set 1529:{\displaystyle x\,R\,y} 1102:. In this case we call 978:{\displaystyle \Vdash } 890:(not only a variable). 433:is a set of subsets of 201:more precise citations. 5205:Neighborhood semantics 5182: 5149: 5116: 5115:{\displaystyle a\in A} 5087: 5037: 5017: 4993: 4973: 4947: 4927: 4874: 4816: 4748: 4695: 4639: 4613: 4549: 4498: 4441: 4413: 4393: 4369: 4349: 4291:JĂłnsson–Tarski duality 4279:contravariant functors 4271: 4238: 4202: 4160: 4138: 4116: 4071: 4051: 4028: 3949: 3929: 3905: 3876: 3856: 3830: 3806: 3768:. The Boolean algebra 3762: 3704: 3645: 3616: 3590: 3540: 3520: 3456: 3436: 3389: 3381: 3372:JĂłnsson–Tarski duality 3362: 3338: 3314: 3294: 3274: 3234: 3214: 3174: 3154: 3126: 3072: 2960: 2940: 2901: 2821: 2775: 2722: 2627: 2582: 2562: 2517: 2497: 2451: 2450:{\displaystyle i\in I} 2425: 2343: 2342:{\displaystyle A\in W} 2317: 2269: 2237: 2205: 2185: 2165: 2118: 2062: 2024: 2004: 1984: 1964: 1932: 1906:, if the Kripke frame 1900: 1850: 1797: 1714: 1694: 1653: 1586: 1556: 1530: 1502: 1436: 1410: 1346: 1285: 1261: 1228: 1177: 1138: 1118: 1096: 1074: 1050: 1034:is valid in the frame 1028: 1005: 1004:{\displaystyle x\in F} 979: 959: 933: 907: 884: 860: 840: 796: 772: 757:propositional variable 749: 696: 670: 638: 600: 572: 486: 447: 427: 407: 383: 363: 331: 5183: 5150: 5117: 5088: 5038: 5018: 4994: 4992:{\displaystyle \leq } 4974: 4948: 4928: 4875: 4817: 4749: 4696: 4651:, if every subset of 4640: 4614: 4550: 4499: 4442: 4414: 4394: 4370: 4368:{\displaystyle \leq } 4350: 4309:Intuitionistic frames 4272: 4239: 4203: 4161: 4139: 4117: 4072: 4052: 4037:for all ultrafilters 4029: 3950: 3930: 3906: 3877: 3857: 3831: 3807: 3763: 3710:to any modal algebra 3705: 3646: 3617: 3591: 3541: 3539:{\displaystyle \Box } 3521: 3457: 3437: 3387: 3379: 3363: 3339: 3315: 3295: 3275: 3235: 3215: 3175: 3155: 3127: 3073: 2961: 2959:{\displaystyle \sim } 2941: 2902: 2822: 2776: 2723: 2628: 2583: 2563: 2518: 2498: 2452: 2426: 2344: 2318: 2270: 2238: 2206: 2186: 2166: 2119: 2063: 2025: 2010:closed upwards under 2005: 1985: 1965: 1933: 1901: 1851: 1798: 1715: 1695: 1654: 1587: 1557: 1542:, if every subset of 1531: 1503: 1437: 1411: 1347: 1286: 1262: 1229: 1178: 1139: 1119: 1097: 1075: 1051: 1029: 1006: 980: 960: 934: 908: 885: 861: 841: 797: 773: 750: 697: 680:in the general frame 671: 639: 601: 573: 487: 485:{\displaystyle \Box } 448: 428: 408: 384: 364: 332: 5159: 5126: 5100: 5050: 5027: 5007: 4983: 4961: 4937: 4884: 4826: 4761: 4712: 4655: 4623: 4566: 4513: 4458: 4431: 4403: 4383: 4359: 4321: 4248: 4215: 4170: 4148: 4126: 4084: 4061: 4041: 3962: 3939: 3919: 3886: 3866: 3844: 3820: 3772: 3714: 3661: 3626: 3604: 3550: 3530: 3473: 3446: 3400: 3352: 3328: 3304: 3284: 3244: 3224: 3184: 3164: 3144: 3083: 2973: 2950: 2914: 2837: 2829:equivalence relation 2785: 2739: 2640: 2592: 2572: 2527: 2507: 2461: 2435: 2361: 2327: 2282: 2247: 2215: 2195: 2175: 2139: 2075: 2034: 2014: 1994: 1974: 1942: 1910: 1864: 1814: 1727: 1704: 1666: 1623: 1576: 1546: 1512: 1452: 1420: 1363: 1310: 1275: 1238: 1187: 1155: 1128: 1106: 1084: 1064: 1038: 1018: 989: 969: 943: 921: 897: 874: 850: 806: 786: 762: 709: 684: 648: 610: 590: 496: 476: 437: 417: 397: 373: 341: 295: 81:improve this article 5223:Patrick Blackburn, 2781:is a refined frame 2171:is a function from 1619:Every Kripke model 1435:{\displaystyle x=y} 289:modal general frame 277:algebraic semantics 5227:, and Yde Venema, 5178: 5145: 5112: 5083: 5033: 5013: 4989: 4969: 4953:is the set of all 4943: 4923: 4870: 4812: 4744: 4691: 4635: 4609: 4545: 4494: 4437: 4409: 4389: 4365: 4345: 4267: 4234: 4198: 4156: 4134: 4112: 4067: 4047: 4024: 3945: 3925: 3901: 3872: 3852: 3836:is the set of all 3826: 3802: 3758: 3700: 3641: 3612: 3586: 3536: 3516: 3452: 3432: 3390: 3382: 3368:) is descriptive. 3358: 3334: 3310: 3290: 3270: 3230: 3210: 3170: 3150: 3122: 3068: 2956: 2936: 2897: 2817: 2771: 2718: 2623: 2578: 2558: 2513: 2493: 2447: 2421: 2339: 2313: 2265: 2233: 2201: 2181: 2161: 2114: 2058: 2020: 2000: 1980: 1960: 1928: 1896: 1858:generated subframe 1846: 1793: 1781: 1779: is a formula 1710: 1690: 1662:the general frame 1649: 1582: 1552: 1526: 1498: 1432: 1406: 1342: 1281: 1257: 1224: 1173: 1134: 1114: 1092: 1070: 1046: 1024: 1013:normal modal logic 1001: 975: 955: 929: 903: 880: 856: 836: 792: 768: 745: 692: 666: 634: 596: 568: 482: 443: 423: 403: 379: 359: 327: 174:list of references 5260:Concepts in logic 5036:{\displaystyle F} 5016:{\displaystyle V} 4946:{\displaystyle F} 4440:{\displaystyle F} 4412:{\displaystyle V} 4392:{\displaystyle F} 4277:become a pair of 4070:{\displaystyle y} 4050:{\displaystyle x} 3948:{\displaystyle R} 3928:{\displaystyle F} 3875:{\displaystyle V} 3829:{\displaystyle F} 3622:, and denoted by 3466:of the power set 3455:{\displaystyle V} 3361:{\displaystyle L} 3337:{\displaystyle L} 3313:{\displaystyle L} 3293:{\displaystyle L} 3233:{\displaystyle L} 3173:{\displaystyle L} 3153:{\displaystyle L} 2581:{\displaystyle R} 2516:{\displaystyle F} 2204:{\displaystyle G} 2184:{\displaystyle F} 2023:{\displaystyle R} 2003:{\displaystyle F} 1983:{\displaystyle G} 1780: 1713:{\displaystyle V} 1585:{\displaystyle V} 1555:{\displaystyle V} 1284:{\displaystyle F} 1137:{\displaystyle L} 1073:{\displaystyle L} 1027:{\displaystyle L} 985:, and all points 906:{\displaystyle A} 883:{\displaystyle A} 859:{\displaystyle V} 802:then ensure that 795:{\displaystyle V} 771:{\displaystyle p} 599:{\displaystyle V} 586:. The purpose of 446:{\displaystyle F} 426:{\displaystyle V} 406:{\displaystyle F} 382:{\displaystyle R} 245: 244: 237: 227: 226: 219: 157: 156: 149: 131: 54: 5267: 5255:Duality theories 5225:Maarten de Rijke 5187: 5185: 5184: 5179: 5177: 5176: 5154: 5152: 5151: 5146: 5144: 5143: 5121: 5119: 5118: 5113: 5092: 5090: 5089: 5084: 5042: 5040: 5039: 5034: 5022: 5020: 5019: 5014: 4998: 4996: 4995: 4990: 4978: 4976: 4975: 4970: 4968: 4952: 4950: 4949: 4944: 4932: 4930: 4929: 4924: 4898: 4897: 4892: 4879: 4877: 4876: 4871: 4833: 4821: 4819: 4818: 4813: 4775: 4774: 4769: 4753: 4751: 4750: 4745: 4719: 4700: 4698: 4697: 4692: 4644: 4642: 4641: 4636: 4618: 4616: 4615: 4610: 4554: 4552: 4551: 4546: 4520: 4503: 4501: 4500: 4495: 4446: 4444: 4443: 4438: 4418: 4416: 4415: 4410: 4398: 4396: 4395: 4390: 4374: 4372: 4371: 4366: 4354: 4352: 4351: 4346: 4276: 4274: 4273: 4268: 4266: 4265: 4243: 4241: 4240: 4235: 4233: 4232: 4207: 4205: 4204: 4199: 4197: 4196: 4187: 4186: 4181: 4165: 4163: 4162: 4157: 4155: 4143: 4141: 4140: 4135: 4133: 4121: 4119: 4118: 4113: 4111: 4110: 4101: 4100: 4095: 4076: 4074: 4073: 4068: 4056: 4054: 4053: 4048: 4033: 4031: 4030: 4025: 3954: 3952: 3951: 3946: 3934: 3932: 3931: 3926: 3911:consists of the 3910: 3908: 3907: 3902: 3900: 3899: 3894: 3881: 3879: 3878: 3873: 3861: 3859: 3858: 3853: 3851: 3835: 3833: 3832: 3827: 3811: 3809: 3808: 3803: 3767: 3765: 3764: 3759: 3721: 3709: 3707: 3706: 3701: 3675: 3674: 3669: 3650: 3648: 3647: 3642: 3640: 3639: 3634: 3621: 3619: 3618: 3613: 3611: 3595: 3593: 3592: 3587: 3545: 3543: 3542: 3537: 3525: 3523: 3522: 3517: 3485: 3484: 3461: 3459: 3458: 3453: 3441: 3439: 3438: 3433: 3407: 3367: 3365: 3364: 3359: 3343: 3341: 3340: 3335: 3319: 3317: 3316: 3311: 3299: 3297: 3296: 3291: 3279: 3277: 3276: 3271: 3266: 3239: 3237: 3236: 3231: 3219: 3217: 3216: 3211: 3206: 3179: 3177: 3176: 3171: 3159: 3157: 3156: 3151: 3131: 3129: 3128: 3123: 3098: 3093: 3077: 3075: 3074: 3069: 3007: 3002: 2991: 2986: 2965: 2963: 2962: 2957: 2945: 2943: 2942: 2937: 2935: 2930: 2906: 2904: 2903: 2898: 2826: 2824: 2823: 2818: 2792: 2780: 2778: 2777: 2772: 2746: 2727: 2725: 2724: 2719: 2708: 2707: 2695: 2694: 2632: 2630: 2629: 2624: 2607: 2606: 2588:is the union of 2587: 2585: 2584: 2579: 2567: 2565: 2564: 2559: 2542: 2541: 2522: 2520: 2519: 2514: 2502: 2500: 2499: 2494: 2468: 2456: 2454: 2453: 2448: 2430: 2428: 2427: 2422: 2417: 2416: 2404: 2403: 2391: 2390: 2375: 2374: 2369: 2348: 2346: 2345: 2340: 2322: 2320: 2319: 2314: 2297: 2296: 2274: 2272: 2271: 2266: 2242: 2240: 2239: 2234: 2210: 2208: 2207: 2202: 2190: 2188: 2187: 2182: 2170: 2168: 2167: 2162: 2160: 2152: 2133:bounded morphism 2123: 2121: 2120: 2115: 2067: 2065: 2064: 2059: 2029: 2027: 2026: 2021: 2009: 2007: 2006: 2001: 1989: 1987: 1986: 1981: 1969: 1967: 1966: 1961: 1937: 1935: 1934: 1929: 1905: 1903: 1902: 1897: 1871: 1855: 1853: 1852: 1847: 1821: 1808:p-morphic images 1802: 1800: 1799: 1794: 1789: 1788: 1782: 1778: 1742: 1741: 1719: 1717: 1716: 1711: 1699: 1697: 1696: 1691: 1658: 1656: 1655: 1650: 1645: 1591: 1589: 1588: 1583: 1561: 1559: 1558: 1553: 1535: 1533: 1532: 1527: 1507: 1505: 1504: 1499: 1441: 1439: 1438: 1433: 1415: 1413: 1412: 1407: 1351: 1349: 1348: 1343: 1317: 1290: 1288: 1287: 1282: 1266: 1264: 1263: 1258: 1247: 1246: 1233: 1231: 1230: 1225: 1211: 1210: 1182: 1180: 1179: 1174: 1143: 1141: 1140: 1135: 1123: 1121: 1120: 1115: 1113: 1101: 1099: 1098: 1093: 1091: 1079: 1077: 1076: 1071: 1055: 1053: 1052: 1047: 1045: 1033: 1031: 1030: 1025: 1010: 1008: 1007: 1002: 984: 982: 981: 976: 964: 962: 961: 956: 938: 936: 935: 930: 928: 912: 910: 909: 904: 889: 887: 886: 881: 865: 863: 862: 857: 845: 843: 842: 837: 801: 799: 798: 793: 777: 775: 774: 769: 754: 752: 751: 746: 701: 699: 698: 693: 691: 675: 673: 672: 667: 643: 641: 640: 635: 605: 603: 602: 597: 577: 575: 574: 569: 491: 489: 488: 483: 452: 450: 449: 444: 432: 430: 429: 424: 412: 410: 409: 404: 388: 386: 385: 380: 368: 366: 365: 360: 336: 334: 333: 328: 302: 273:Kripke semantics 240: 233: 222: 215: 211: 208: 202: 197:this article by 188:inline citations 167: 166: 159: 152: 145: 141: 138: 132: 130: 89: 65: 57: 46: 24: 23: 16: 5275: 5274: 5270: 5269: 5268: 5266: 5265: 5264: 5235: 5234: 5213: 5201: 5193:modal companion 5168: 5157: 5156: 5135: 5124: 5123: 5098: 5097: 5048: 5047: 5025: 5024: 5005: 5004: 4981: 4980: 4979:, the ordering 4959: 4958: 4935: 4934: 4887: 4882: 4881: 4824: 4823: 4764: 4759: 4758: 4756:Heyting algebra 4710: 4709: 4653: 4652: 4621: 4620: 4564: 4563: 4511: 4510: 4456: 4455: 4429: 4428: 4401: 4400: 4381: 4380: 4357: 4356: 4319: 4318: 4311: 4257: 4246: 4245: 4224: 4213: 4212: 4188: 4176: 4168: 4167: 4146: 4145: 4124: 4123: 4102: 4090: 4082: 4081: 4059: 4058: 4039: 4038: 3960: 3959: 3937: 3936: 3917: 3916: 3889: 3884: 3883: 3864: 3863: 3842: 3841: 3818: 3817: 3770: 3769: 3712: 3711: 3664: 3659: 3658: 3629: 3624: 3623: 3602: 3601: 3548: 3547: 3528: 3527: 3471: 3470: 3468:Boolean algebra 3444: 3443: 3398: 3397: 3374: 3350: 3349: 3346:canonical frame 3326: 3325: 3324:frame. Indeed, 3302: 3301: 3282: 3281: 3242: 3241: 3222: 3221: 3182: 3181: 3162: 3161: 3142: 3141: 3138: 3081: 3080: 2971: 2970: 2948: 2947: 2912: 2911: 2835: 2834: 2783: 2782: 2737: 2736: 2699: 2686: 2638: 2637: 2598: 2590: 2589: 2570: 2569: 2533: 2525: 2524: 2505: 2504: 2459: 2458: 2457:, is the frame 2433: 2432: 2408: 2395: 2382: 2364: 2359: 2358: 2325: 2324: 2285: 2280: 2279: 2245: 2244: 2213: 2212: 2193: 2192: 2173: 2172: 2137: 2136: 2073: 2072: 2032: 2031: 2012: 2011: 1992: 1991: 1990:is a subset of 1972: 1971: 1940: 1939: 1908: 1907: 1862: 1861: 1812: 1811: 1725: 1724: 1702: 1701: 1664: 1663: 1621: 1620: 1617: 1574: 1573: 1544: 1543: 1510: 1509: 1450: 1449: 1418: 1417: 1361: 1360: 1308: 1307: 1297: 1295:Types of frames 1273: 1272: 1236: 1235: 1185: 1184: 1153: 1152: 1151:A Kripke frame 1126: 1125: 1104: 1103: 1082: 1081: 1062: 1061: 1036: 1035: 1016: 1015: 987: 986: 967: 966: 941: 940: 919: 918: 895: 894: 872: 871: 848: 847: 804: 803: 784: 783: 760: 759: 707: 706: 682: 681: 646: 645: 608: 607: 588: 587: 494: 493: 474: 473: 435: 434: 415: 414: 395: 394: 391:binary relation 371: 370: 339: 338: 293: 292: 285: 241: 230: 229: 228: 223: 212: 206: 203: 192: 178:related reading 168: 164: 153: 142: 136: 133: 96:"General frame" 90: 88: 78: 66: 25: 21: 12: 11: 5: 5273: 5271: 5263: 5262: 5257: 5252: 5247: 5237: 5236: 5233: 5232: 5221: 5212: 5209: 5208: 5207: 5200: 5197: 5175: 5171: 5167: 5164: 5142: 5138: 5134: 5131: 5111: 5108: 5105: 5094: 5093: 5082: 5079: 5076: 5073: 5070: 5067: 5064: 5061: 5058: 5055: 5032: 5012: 4988: 4967: 4942: 4922: 4919: 4916: 4913: 4910: 4907: 4904: 4901: 4896: 4891: 4869: 4866: 4863: 4860: 4857: 4854: 4851: 4848: 4845: 4842: 4839: 4836: 4832: 4811: 4808: 4805: 4802: 4799: 4796: 4793: 4790: 4787: 4784: 4781: 4778: 4773: 4768: 4743: 4740: 4737: 4734: 4731: 4728: 4725: 4722: 4718: 4703: 4702: 4690: 4687: 4684: 4681: 4678: 4675: 4672: 4669: 4666: 4663: 4660: 4646: 4634: 4631: 4628: 4608: 4605: 4602: 4599: 4596: 4593: 4590: 4587: 4584: 4580: 4577: 4574: 4571: 4544: 4541: 4538: 4535: 4532: 4529: 4526: 4523: 4519: 4506: 4505: 4493: 4490: 4487: 4484: 4481: 4478: 4475: 4472: 4469: 4466: 4463: 4454:the operation 4452: 4436: 4408: 4388: 4364: 4344: 4341: 4338: 4335: 4332: 4329: 4326: 4310: 4307: 4295:Bjarni JĂłnsson 4264: 4260: 4256: 4253: 4231: 4227: 4223: 4220: 4195: 4191: 4185: 4180: 4175: 4154: 4132: 4109: 4105: 4099: 4094: 4089: 4066: 4046: 4035: 4034: 4023: 4020: 4017: 4014: 4011: 4008: 4005: 4002: 3999: 3996: 3992: 3989: 3986: 3983: 3979: 3975: 3971: 3967: 3955:is defined by 3944: 3924: 3898: 3893: 3871: 3850: 3825: 3801: 3798: 3795: 3792: 3789: 3786: 3783: 3780: 3777: 3757: 3754: 3751: 3748: 3745: 3742: 3739: 3736: 3733: 3730: 3727: 3724: 3720: 3699: 3696: 3693: 3690: 3687: 3684: 3681: 3678: 3673: 3668: 3638: 3633: 3610: 3585: 3582: 3579: 3576: 3573: 3570: 3567: 3564: 3561: 3558: 3555: 3535: 3515: 3512: 3509: 3506: 3503: 3500: 3497: 3494: 3491: 3488: 3483: 3478: 3451: 3431: 3428: 3425: 3422: 3419: 3416: 3413: 3410: 3406: 3394:modal algebras 3373: 3370: 3357: 3333: 3309: 3289: 3269: 3265: 3261: 3258: 3255: 3252: 3249: 3229: 3209: 3205: 3201: 3198: 3195: 3192: 3189: 3169: 3149: 3137: 3134: 3133: 3132: 3121: 3118: 3115: 3112: 3108: 3104: 3101: 3097: 3092: 3088: 3078: 3067: 3064: 3061: 3058: 3055: 3052: 3049: 3046: 3043: 3040: 3037: 3033: 3030: 3027: 3024: 3020: 3016: 3013: 3010: 3006: 3001: 2997: 2994: 2990: 2985: 2981: 2978: 2966:. Then we put 2955: 2934: 2929: 2925: 2922: 2919: 2908: 2907: 2896: 2893: 2890: 2887: 2884: 2881: 2878: 2875: 2872: 2869: 2865: 2862: 2859: 2856: 2852: 2848: 2845: 2842: 2816: 2813: 2810: 2807: 2804: 2801: 2798: 2795: 2791: 2770: 2767: 2764: 2761: 2758: 2755: 2752: 2749: 2745: 2729: 2728: 2717: 2714: 2711: 2706: 2702: 2698: 2693: 2689: 2685: 2682: 2679: 2675: 2672: 2669: 2666: 2663: 2660: 2657: 2654: 2651: 2648: 2645: 2622: 2619: 2616: 2613: 2610: 2605: 2601: 2597: 2577: 2557: 2554: 2551: 2548: 2545: 2540: 2536: 2532: 2512: 2492: 2489: 2486: 2483: 2480: 2477: 2474: 2471: 2467: 2446: 2443: 2440: 2420: 2415: 2411: 2407: 2402: 2398: 2394: 2389: 2385: 2381: 2378: 2373: 2368: 2355:disjoint union 2351: 2350: 2338: 2335: 2332: 2312: 2309: 2306: 2303: 2300: 2295: 2292: 2288: 2264: 2261: 2258: 2255: 2252: 2232: 2229: 2226: 2223: 2220: 2200: 2180: 2159: 2155: 2151: 2147: 2144: 2125: 2124: 2113: 2110: 2107: 2104: 2101: 2098: 2095: 2092: 2089: 2086: 2083: 2080: 2057: 2054: 2051: 2048: 2045: 2042: 2039: 2019: 1999: 1979: 1959: 1956: 1953: 1950: 1947: 1927: 1924: 1921: 1918: 1915: 1895: 1892: 1889: 1886: 1883: 1880: 1877: 1874: 1870: 1845: 1842: 1839: 1836: 1833: 1830: 1827: 1824: 1820: 1804: 1803: 1792: 1787: 1775: 1772: 1769: 1766: 1763: 1760: 1757: 1754: 1751: 1748: 1745: 1740: 1735: 1732: 1720:is defined as 1709: 1689: 1686: 1683: 1680: 1677: 1674: 1671: 1648: 1644: 1640: 1637: 1634: 1631: 1628: 1616: 1613: 1606: 1605: 1599: 1593: 1581: 1567: 1551: 1537: 1525: 1521: 1517: 1497: 1494: 1491: 1488: 1485: 1482: 1479: 1476: 1473: 1470: 1466: 1463: 1460: 1457: 1443: 1431: 1428: 1425: 1405: 1402: 1399: 1396: 1393: 1390: 1387: 1384: 1381: 1377: 1374: 1371: 1368: 1357:differentiated 1341: 1338: 1335: 1332: 1329: 1326: 1323: 1320: 1316: 1296: 1293: 1280: 1256: 1253: 1250: 1245: 1223: 1220: 1217: 1214: 1209: 1204: 1201: 1198: 1195: 1192: 1172: 1169: 1166: 1163: 1160: 1133: 1112: 1090: 1069: 1044: 1023: 1000: 997: 994: 974: 954: 951: 948: 927: 902: 879: 855: 835: 832: 829: 826: 823: 820: 817: 814: 811: 791: 780: 779: 767: 744: 741: 738: 735: 732: 729: 726: 723: 720: 717: 714: 690: 665: 662: 659: 656: 653: 633: 630: 627: 624: 621: 618: 615: 595: 580: 579: 567: 564: 561: 558: 555: 552: 549: 545: 541: 538: 534: 531: 528: 525: 522: 519: 516: 513: 510: 507: 504: 501: 481: 472:the operation 470: 442: 422: 402: 378: 358: 355: 352: 349: 346: 326: 323: 320: 317: 314: 311: 308: 305: 301: 284: 281: 253:general frames 243: 242: 225: 224: 182:external links 171: 169: 162: 155: 154: 69: 67: 60: 55: 29: 28: 26: 19: 13: 10: 9: 6: 4: 3: 2: 5272: 5261: 5258: 5256: 5253: 5251: 5248: 5246: 5243: 5242: 5240: 5230: 5226: 5222: 5219: 5215: 5214: 5210: 5206: 5203: 5202: 5198: 5196: 5194: 5189: 5173: 5165: 5140: 5132: 5109: 5106: 5103: 5080: 5074: 5071: 5068: 5065: 5062: 5059: 5056: 5046: 5045: 5044: 5030: 5010: 5002: 4986: 4956: 4955:prime filters 4940: 4917: 4914: 4911: 4908: 4905: 4899: 4894: 4864: 4861: 4855: 4852: 4849: 4846: 4843: 4840: 4834: 4803: 4797: 4794: 4791: 4788: 4785: 4782: 4776: 4771: 4757: 4738: 4735: 4732: 4729: 4726: 4720: 4706: 4685: 4682: 4679: 4676: 4673: 4670: 4667: 4661: 4658: 4650: 4647: 4632: 4629: 4626: 4603: 4600: 4597: 4591: 4588: 4585: 4578: 4575: 4572: 4561: 4558: 4557: 4556: 4539: 4536: 4533: 4530: 4527: 4521: 4488: 4485: 4482: 4479: 4473: 4470: 4467: 4461: 4453: 4450: 4449: 4448: 4434: 4426: 4422: 4421:upper subsets 4406: 4386: 4378: 4377:partial order 4362: 4339: 4336: 4333: 4330: 4327: 4316: 4308: 4306: 4304: 4300: 4299:Alfred Tarski 4296: 4292: 4288: 4284: 4280: 4262: 4254: 4229: 4221: 4209: 4193: 4183: 4107: 4097: 4078: 4064: 4044: 4018: 4015: 4012: 4006: 4003: 4000: 3997: 3990: 3987: 3984: 3973: 3969: 3965: 3958: 3957: 3956: 3942: 3922: 3914: 3896: 3869: 3839: 3823: 3815: 3796: 3793: 3790: 3787: 3784: 3781: 3778: 3752: 3749: 3746: 3743: 3740: 3737: 3734: 3731: 3728: 3722: 3694: 3691: 3688: 3685: 3682: 3676: 3671: 3657: 3652: 3636: 3599: 3580: 3577: 3574: 3571: 3568: 3565: 3562: 3559: 3556: 3533: 3510: 3507: 3504: 3501: 3498: 3495: 3489: 3469: 3465: 3449: 3426: 3423: 3420: 3417: 3414: 3408: 3395: 3386: 3378: 3371: 3369: 3355: 3347: 3331: 3323: 3307: 3287: 3263: 3259: 3256: 3253: 3250: 3227: 3203: 3199: 3196: 3193: 3190: 3167: 3147: 3135: 3119: 3116: 3113: 3110: 3102: 3099: 3095: 3090: 3086: 3079: 3065: 3059: 3056: 3053: 3047: 3044: 3041: 3038: 3031: 3028: 3025: 3014: 3011: 3004: 2999: 2995: 2992: 2988: 2983: 2979: 2969: 2968: 2967: 2953: 2932: 2927: 2923: 2920: 2917: 2894: 2888: 2885: 2882: 2876: 2873: 2870: 2863: 2860: 2857: 2846: 2843: 2840: 2833: 2832: 2831: 2830: 2811: 2808: 2805: 2802: 2799: 2793: 2765: 2762: 2759: 2756: 2753: 2747: 2734: 2715: 2704: 2700: 2696: 2691: 2687: 2683: 2680: 2673: 2670: 2667: 2661: 2658: 2655: 2652: 2646: 2643: 2636: 2635: 2634: 2617: 2614: 2611: 2608: 2603: 2599: 2575: 2552: 2549: 2546: 2543: 2538: 2534: 2510: 2487: 2484: 2481: 2478: 2475: 2469: 2444: 2441: 2438: 2413: 2409: 2405: 2400: 2396: 2392: 2387: 2383: 2376: 2371: 2356: 2336: 2333: 2330: 2310: 2307: 2301: 2293: 2290: 2286: 2278: 2277: 2276: 2259: 2256: 2253: 2227: 2224: 2221: 2198: 2178: 2145: 2142: 2134: 2130: 2111: 2105: 2102: 2099: 2096: 2093: 2090: 2087: 2081: 2078: 2071: 2070: 2069: 2055: 2052: 2049: 2046: 2043: 2040: 2037: 2017: 1997: 1977: 1954: 1951: 1948: 1922: 1919: 1916: 1890: 1887: 1884: 1881: 1878: 1872: 1859: 1840: 1837: 1834: 1831: 1828: 1822: 1809: 1790: 1773: 1770: 1764: 1761: 1758: 1755: 1752: 1749: 1746: 1733: 1730: 1723: 1722: 1721: 1707: 1684: 1681: 1678: 1675: 1672: 1661: 1642: 1638: 1635: 1632: 1629: 1614: 1612: 1609: 1603: 1600: 1597: 1594: 1579: 1571: 1568: 1565: 1549: 1541: 1538: 1523: 1519: 1515: 1492: 1489: 1486: 1480: 1477: 1474: 1471: 1464: 1461: 1458: 1447: 1444: 1429: 1426: 1423: 1400: 1397: 1394: 1388: 1385: 1382: 1375: 1372: 1369: 1358: 1355: 1354: 1353: 1336: 1333: 1330: 1327: 1324: 1318: 1304: 1302: 1294: 1292: 1278: 1270: 1251: 1215: 1202: 1199: 1196: 1193: 1167: 1164: 1161: 1149: 1147: 1131: 1080:are valid in 1067: 1059: 1021: 1014: 998: 995: 992: 972: 952: 949: 946: 916: 900: 891: 877: 869: 853: 830: 827: 824: 821: 818: 815: 812: 789: 765: 758: 742: 739: 733: 730: 727: 724: 721: 718: 715: 705: 704: 703: 679: 660: 657: 654: 628: 625: 622: 619: 616: 593: 585: 559: 556: 553: 547: 543: 539: 532: 529: 526: 520: 517: 514: 511: 505: 502: 499: 492:, defined by 479: 471: 468: 464: 460: 456: 455: 454: 440: 420: 400: 392: 376: 353: 350: 347: 321: 318: 315: 312: 309: 303: 290: 282: 280: 278: 274: 270: 266: 262: 261:Kripke frames 258: 254: 250: 239: 236: 221: 218: 210: 207:November 2020 200: 196: 190: 189: 183: 179: 175: 170: 161: 160: 151: 148: 140: 137:November 2020 129: 126: 122: 119: 115: 112: 108: 105: 101: 98: â€“  97: 93: 92:Find sources: 86: 82: 76: 75: 70:This article 68: 64: 59: 58: 53: 51: 44: 43: 38: 37: 32: 27: 18: 17: 5250:Model theory 5228: 5217: 5190: 5095: 5043:of the form 4707: 4704: 4648: 4559: 4507: 4424: 4419:is a set of 4317:is a triple 4314: 4312: 4290: 4281:between the 4210: 4079: 4036: 3838:ultrafilters 3655: 3653: 3598:dual algebra 3597: 3391: 3345: 3321: 3139: 3136:Completeness 2909: 2732: 2730: 2354: 2352: 2132: 2128: 2126: 1857: 1805: 1659: 1618: 1610: 1607: 1601: 1595: 1569: 1539: 1445: 1356: 1305: 1300: 1298: 1267:denotes the 1150: 1145: 914: 892: 867: 781: 677: 581: 459:intersection 291:is a triple 288: 286: 269:intermediate 256: 252: 246: 231: 213: 204: 193:Please help 185: 143: 134: 124: 117: 110: 103: 91: 79:Please help 74:verification 71: 47: 40: 34: 33:Please help 30: 5245:Modal logic 5229:Modal Logic 5218:Modal Logic 3915:subsets of 3814:Stone space 3322:descriptive 2735:of a frame 1860:of a frame 1602:descriptive 846:belongs to 393:on the set 255:(or simply 199:introducing 5239:Categories 5211:References 4555:is called 3862:. The set 3656:dual frame 3464:subalgebra 2733:refinement 2323:for every 2129:p-morphism 1352:is called 893:A formula 755:for every 678:admissible 467:complement 283:Definition 107:newspapers 36:improve it 5166:⋅ 5133:⋅ 5107:∈ 5072:∈ 5066:∣ 5060:∈ 5001:inclusion 4987:≤ 4921:⟩ 4912:≤ 4903:⟨ 4868:⟩ 4859:→ 4853:∨ 4847:∧ 4838:⟨ 4810:⟩ 4807:∅ 4801:→ 4795:∪ 4789:∩ 4780:⟨ 4742:⟩ 4733:≤ 4724:⟨ 4683:∈ 4677:∣ 4671:− 4662:∪ 4630:≤ 4601:∈ 4595:⇔ 4589:∈ 4576:∈ 4570:∀ 4543:⟩ 4534:≤ 4525:⟨ 4486:∪ 4480:− 4474:◻ 4465:→ 4363:≤ 4343:⟩ 4334:≤ 4325:⟨ 4255:⋅ 4222:⋅ 4016:∈ 4010:⇒ 4004:∈ 3998:◻ 3988:∈ 3982:∀ 3978:⟺ 3800:⟩ 3797:− 3791:∨ 3785:∧ 3776:⟨ 3756:⟩ 3753:◻ 3747:− 3741:∨ 3735:∧ 3726:⟨ 3698:⟩ 3680:⟨ 3584:⟩ 3581:◻ 3575:− 3569:∪ 3563:∩ 3554:⟨ 3534:◻ 3514:⟩ 3511:− 3505:∪ 3499:∩ 3477:⟨ 3430:⟩ 3412:⟨ 3268:⟩ 3264:⊩ 3248:⟨ 3208:⟩ 3204:⊩ 3188:⟨ 3114:∈ 3107:⟺ 3100:∈ 3096:∼ 3057:∈ 3051:⇒ 3045:◻ 3042:∈ 3029:∈ 3023:∀ 3019:⟺ 3012:∈ 3009:⟩ 3005:∼ 2989:∼ 2977:⟨ 2954:∼ 2933:∼ 2886:∈ 2880:⇔ 2874:∈ 2861:∈ 2855:∀ 2851:⟺ 2844:∼ 2815:⟩ 2797:⟨ 2769:⟩ 2751:⟨ 2697:∈ 2684:∩ 2671:∈ 2665:∀ 2662:∣ 2656:⊆ 2615:∈ 2609:∣ 2550:∈ 2544:∣ 2491:⟩ 2473:⟨ 2442:∈ 2419:⟩ 2380:⟨ 2334:∈ 2308:∈ 2291:− 2263:⟩ 2251:⟨ 2231:⟩ 2219:⟨ 2154:→ 2146:: 2103:∈ 2097:∣ 2091:∩ 2053:× 2047:∩ 1958:⟩ 1946:⟨ 1926:⟩ 1914:⟨ 1894:⟩ 1876:⟨ 1844:⟩ 1826:⟨ 1771:∣ 1762:⊩ 1756:∣ 1750:∈ 1688:⟩ 1670:⟨ 1647:⟩ 1643:⊩ 1627:⟨ 1562:with the 1490:∈ 1484:⇒ 1478:◻ 1475:∈ 1462:∈ 1456:∀ 1398:∈ 1392:⇔ 1386:∈ 1373:∈ 1367:∀ 1340:⟩ 1322:⟨ 1269:power set 1222:⟩ 1191:⟨ 1171:⟩ 1159:⟨ 996:∈ 973:⊩ 950:⊩ 828:⊩ 822:∣ 816:∈ 740:∈ 731:⊩ 725:∣ 719:∈ 664:⟩ 652:⟨ 632:⟩ 629:⊩ 614:⟨ 557:∈ 551:→ 530:∈ 524:∀ 521:∣ 515:∈ 500:◻ 480:◻ 357:⟩ 345:⟨ 325:⟩ 307:⟨ 42:talk page 5199:See also 4933:, where 4619:implies 4355:, where 4289:(called 4283:category 2910:and let 2503:, where 1700:, where 1508:implies 1416:implies 1306:A frame 1234:, where 1058:theorems 870:formula 337:, where 4754:is the 4649:compact 4287:duality 2068:), and 1970:(i.e., 1660:induces 1596:refined 1540:compact 413:), and 195:improve 121:scholar 5096:where 5003:, and 4399:, and 4293:after 3913:clopen 3812:has a 3396:. Let 3280:is an 2633:, and 2030:, and 1570:atomic 1301:models 465:, and 259:) are 257:frames 123:  116:  109:  102:  94:  4562:, if 4560:tight 4427:) of 4425:cones 4375:is a 3220:: as 1856:is a 1572:, if 1448:, if 1446:tight 1359:, if 1146:frame 1060:) of 939:, if 915:valid 868:every 702:, if 463:union 389:is a 265:modal 249:logic 180:, or 128:JSTOR 114:books 5155:and 4297:and 4244:and 4057:and 2731:The 2353:The 2243:and 2131:(or 1011:. A 866:for 275:and 267:and 100:news 4999:is 4957:of 4379:on 3840:of 3600:of 3348:of 2191:to 1271:of 1124:an 917:in 913:is 676:is 247:In 83:by 5241:: 5195:. 4305:. 4208:. 4077:. 3651:. 2568:, 2431:, 2135:) 2127:A 1291:. 1148:. 461:, 287:A 251:, 184:, 176:, 45:. 5174:+ 5170:) 5163:( 5141:+ 5137:) 5130:( 5110:A 5104:a 5081:, 5078:} 5075:x 5069:a 5063:F 5057:x 5054:{ 5031:F 5011:V 4966:A 4941:F 4918:V 4915:, 4909:, 4906:F 4900:= 4895:+ 4890:A 4865:0 4862:, 4856:, 4850:, 4844:, 4841:A 4835:= 4831:A 4804:, 4798:, 4792:, 4786:, 4783:V 4777:= 4772:+ 4767:F 4739:V 4736:, 4730:, 4727:F 4721:= 4717:F 4689:} 4686:V 4680:A 4674:A 4668:F 4665:{ 4659:V 4645:, 4633:y 4627:x 4607:) 4604:A 4598:y 4592:A 4586:x 4583:( 4579:V 4573:A 4540:V 4537:, 4531:, 4528:F 4522:= 4518:F 4504:. 4492:) 4489:B 4483:A 4477:( 4471:= 4468:B 4462:A 4435:F 4423:( 4407:V 4387:F 4340:V 4337:, 4331:, 4328:F 4263:+ 4259:) 4252:( 4230:+ 4226:) 4219:( 4194:+ 4190:) 4184:+ 4179:F 4174:( 4153:F 4131:A 4108:+ 4104:) 4098:+ 4093:A 4088:( 4065:y 4045:x 4022:) 4019:y 4013:a 4007:x 4001:a 3995:( 3991:A 3985:a 3974:y 3970:R 3966:x 3943:R 3923:F 3897:+ 3892:A 3870:V 3849:A 3824:F 3794:, 3788:, 3782:, 3779:A 3750:, 3744:, 3738:, 3732:, 3729:A 3723:= 3719:A 3695:V 3692:, 3689:R 3686:, 3683:F 3677:= 3672:+ 3667:A 3637:+ 3632:F 3609:F 3578:, 3572:, 3566:, 3560:, 3557:V 3508:, 3502:, 3496:, 3493:) 3490:F 3487:( 3482:P 3450:V 3427:V 3424:, 3421:R 3418:, 3415:F 3409:= 3405:F 3356:L 3332:L 3308:L 3288:L 3260:, 3257:R 3254:, 3251:F 3228:L 3200:, 3197:R 3194:, 3191:F 3168:L 3148:L 3120:. 3117:V 3111:A 3103:W 3091:/ 3087:A 3066:, 3063:) 3060:A 3054:y 3048:A 3039:x 3036:( 3032:V 3026:A 3015:S 3000:/ 2996:y 2993:, 2984:/ 2980:x 2928:/ 2924:F 2921:= 2918:G 2895:, 2892:) 2889:A 2883:y 2877:A 2871:x 2868:( 2864:V 2858:A 2847:y 2841:x 2812:W 2809:, 2806:S 2803:, 2800:G 2794:= 2790:G 2766:V 2763:, 2760:R 2757:, 2754:F 2748:= 2744:F 2716:. 2713:} 2710:) 2705:i 2701:V 2692:i 2688:F 2681:A 2678:( 2674:I 2668:i 2659:F 2653:A 2650:{ 2647:= 2644:V 2621:} 2618:I 2612:i 2604:i 2600:R 2596:{ 2576:R 2556:} 2553:I 2547:i 2539:i 2535:F 2531:{ 2511:F 2488:V 2485:, 2482:R 2479:, 2476:F 2470:= 2466:F 2445:I 2439:i 2414:i 2410:V 2406:, 2401:i 2397:R 2393:, 2388:i 2384:F 2377:= 2372:i 2367:F 2349:. 2337:W 2331:A 2311:V 2305:] 2302:A 2299:[ 2294:1 2287:f 2260:S 2257:, 2254:G 2228:R 2225:, 2222:F 2199:G 2179:F 2158:G 2150:F 2143:f 2112:. 2109:} 2106:V 2100:A 2094:G 2088:A 2085:{ 2082:= 2079:W 2056:G 2050:G 2044:R 2041:= 2038:S 2018:R 1998:F 1978:G 1955:R 1952:, 1949:F 1923:S 1920:, 1917:G 1891:V 1888:, 1885:R 1882:, 1879:F 1873:= 1869:F 1841:W 1838:, 1835:S 1832:, 1829:G 1823:= 1819:G 1791:. 1786:} 1774:A 1768:} 1765:A 1759:x 1753:F 1747:x 1744:{ 1739:{ 1734:= 1731:V 1708:V 1685:V 1682:, 1679:R 1676:, 1673:F 1639:, 1636:R 1633:, 1630:F 1580:V 1550:V 1536:, 1524:y 1520:R 1516:x 1496:) 1493:A 1487:y 1481:A 1472:x 1469:( 1465:V 1459:A 1442:, 1430:y 1427:= 1424:x 1404:) 1401:A 1395:y 1389:A 1383:x 1380:( 1376:V 1370:A 1337:V 1334:, 1331:R 1328:, 1325:F 1319:= 1315:F 1279:F 1255:) 1252:F 1249:( 1244:P 1219:) 1216:F 1213:( 1208:P 1203:, 1200:R 1197:, 1194:F 1168:R 1165:, 1162:F 1144:- 1132:L 1111:F 1089:F 1068:L 1043:F 1022:L 999:F 993:x 953:A 947:x 926:F 901:A 878:A 854:V 834:} 831:A 825:x 819:F 813:x 810:{ 790:V 778:. 766:p 743:V 737:} 734:p 728:x 722:F 716:x 713:{ 689:F 661:R 658:, 655:F 626:, 623:R 620:, 617:F 594:V 578:. 566:} 563:) 560:A 554:y 548:y 544:R 540:x 537:( 533:F 527:y 518:F 512:x 509:{ 506:= 503:A 469:, 441:F 421:V 401:F 377:R 354:R 351:, 348:F 322:V 319:, 316:R 313:, 310:F 304:= 300:F 238:) 232:( 220:) 214:( 209:) 205:( 191:. 150:) 144:( 139:) 135:( 125:· 118:· 111:· 104:· 77:. 52:) 48:(

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logic
Kripke frames
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algebraic semantics
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