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Morley rank

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408:, edited by D. Haskell et al., Math. Sci. Res. Inst. Publ. 39, Cambridge Univ. Press, New York, 2000. Contains a formal definition of Morley rank. 282: 265:. A formula defining a finite set has Morley rank 0. A formula with Morley rank 1 and Morley degree 1 is called 463: 286: 83:
or −1 or ∞, defined by first recursively defining what it means for a formula to have Morley rank at least
491: 473: 434: 368: 486: 468: 373: 340: 317: 419:, edited by D. Haskell et al., Math. Sci. Res. Inst. Publ. 39, Cambridge Univ. Press, New York, 2000. 226:-saturated models the Morley rank of a subset is the Morley rank of any formula defining the subset. 481: 425: 298:
The empty set has Morley rank −1, and conversely anything of Morley rank −1 is empty.
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is strongly minimal. Morley rank and strongly minimal structures are key tools in the proof of
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A subset has Morley rank 0 if and only if it is finite and non-empty.
443: 343:, except when its components of maximal dimension are linear spaces. 378: 33: 397:, "Groups of finite Morley rank", Oxford Univ. Press (1994) 183: + 1, and is defined to be ∞ if it is at least 129:
has countably infinitely many disjoint definable subsets
206:) the Morley rank is defined to be the Morley rank of 339:of maximal dimension; this is not the same as its 499: 354:, has Morley rank ∞, as it contains a countable 423:Morley, M.D. (1965), "Categoricity in power", 273:structure is one where the trivial formula 358:of definable subsets isomorphic to itself. 285:and in the larger area of model theoretic 44:, generalizing the notion of dimension in 442: 32:), is a means of measuring the size of a 500: 479: 458: 422: 171:The Morley rank is then defined to be 29: 413:Model Theory of Differential Fields 191:, and is defined to be −1 if 13: 417:Model theory, algebra and geometry 406:Model theory, algebra and geometry 249: < ω subsets of rank 198:For a definable subset of a model 70:definable (with parameters) subset 14: 519: 402:Stability theory and its variants 95:The Morley rank is at least 0 if 64:. The Morley rank of a formula 151:, the Morley rank is at least 110:, the Morley rank is at least 1: 464:"Group of finite Morley rank" 435:American Mathematical Society 384: 283:Morley's categoricity theorem 51: 341:degree in algebraic geometry 245:breaks up into no more than 7: 487:Encyclopedia of Mathematics 469:Encyclopedia of Mathematics 404:(2000) pp. 131–148 in 374:Group of finite Morley rank 362: 292: 10: 524: 323:, then the Morley rank of 318:algebraically closed field 415:(2000) pp. 53–63 in 369:Cherlin–Zilber conjecture 327:is the same as its usual 218:elementary extension of 136:, each of rank at least 480:Pillay, Anand (2001) , 426:Trans. Amer. Math. Soc. 331:. The Morley degree of 337:irreducible components 202:(defined by a formula 222:. In particular for ℵ 140: − 1. 26:Michael D. Morley 116:elementary extension 350:, considered as an 175:if it is at least 155:if it is at least 46:algebraic geometry 18:mathematical logic 391:Alexandre Borovik 335:is the number of 187:for all ordinals 179:but not at least 108:successor ordinal 87:for some ordinal 515: 494: 476: 455: 446: 348:rational numbers 287:stability theory 271:strongly minimal 267:strongly minimal 257:is said to have 24:, introduced by 523: 522: 518: 517: 516: 514: 513: 512: 498: 497: 444:10.2307/1994188 387: 365: 329:Krull dimension 295: 225: 213: 134: 54: 12: 11: 5: 521: 511: 510: 496: 495: 477: 456: 420: 409: 398: 386: 383: 382: 381: 376: 371: 364: 361: 360: 359: 356:disjoint union 344: 302: 299: 294: 291: 223: 211: 169: 168: 141: 132: 100: 53: 50: 9: 6: 4: 3: 2: 520: 509: 506: 505: 503: 493: 489: 488: 483: 482:"Morley rank" 478: 475: 471: 470: 465: 461: 460:Pillay, Anand 457: 454: 450: 445: 440: 436: 432: 428: 427: 421: 418: 414: 411:David Marker 410: 407: 403: 399: 396: 392: 389: 388: 380: 377: 375: 372: 370: 367: 366: 357: 353: 349: 345: 342: 338: 334: 330: 326: 322: 319: 315: 311: 310:algebraic set 307: 303: 300: 297: 296: 290: 288: 284: 280: 277: =  276: 272: 268: 264: 260: 259:Morley degree 256: 252: 248: 244: 240: 236: 232: 227: 221: 217: 209: 205: 201: 196: 194: 190: 186: 182: 178: 174: 166: 162: 158: 154: 150: 149:limit ordinal 146: 142: 139: 135: 128: 124: 120: 117: 113: 109: 105: 101: 99:is non-empty. 98: 94: 93: 92: 90: 86: 82: 78: 74: 71: 67: 63: 60:with a model 59: 56:Fix a theory 49: 47: 43: 39: 35: 31: 27: 23: 19: 508:Model theory 485: 467: 430: 424: 416: 405: 332: 324: 320: 313: 305: 278: 274: 270: 262: 258: 254: 250: 246: 242: 238: 234: 230: 228: 219: 207: 203: 199: 197: 192: 188: 184: 180: 176: 172: 170: 164: 160: 156: 152: 144: 137: 130: 126: 122: 118: 111: 103: 96: 88: 84: 76: 72: 65: 61: 57: 55: 21: 15: 437:: 514–538, 352:ordered set 147:a non-zero 114:if in some 68:defining a 22:Morley rank 385:References 195:is empty. 163:less than 125:, the set 52:Definition 492:EMS Press 474:EMS Press 462:(2001) , 395:Ali Nesin 316:, for an 237:has rank 233:defining 216:saturated 502:Category 400:B. Hart 363:See also 293:Examples 210:in any ℵ 159:for all 453:1994188 253:, then 81:ordinal 28: ( 451:  379:U-rank 308:is an 261:  241:, and 79:is an 42:theory 36:of a 34:subset 449:JSTOR 433:(2), 269:. A 40:of a 38:model 393:, 346:The 143:For 102:For 30:1965 439:doi 431:114 312:in 304:If 229:If 121:of 91:. 75:of 16:In 504:: 490:, 484:, 472:, 466:, 447:, 429:, 289:. 106:a 48:. 20:, 441:: 333:V 325:V 321:K 314:K 306:V 279:x 275:x 263:n 255:φ 251:α 247:n 243:S 239:α 235:S 231:φ 224:0 220:M 214:- 212:0 208:φ 204:φ 200:M 193:S 189:α 185:α 181:α 177:α 173:α 167:. 165:α 161:β 157:β 153:α 145:α 138:α 133:i 131:S 127:S 123:M 119:N 112:α 104:α 97:S 89:α 85:α 77:M 73:S 66:φ 62:M 58:T

Index

mathematical logic
Michael D. Morley
1965
subset
model
theory
algebraic geometry
definable (with parameters) subset
ordinal
successor ordinal
elementary extension
limit ordinal
saturated
strongly minimal
Morley's categoricity theorem
stability theory
algebraic set
algebraically closed field
Krull dimension
irreducible components
degree in algebraic geometry
rational numbers
ordered set
disjoint union
Cherlin–Zilber conjecture
Group of finite Morley rank
U-rank
Alexandre Borovik
Ali Nesin
Stability theory and its variants

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