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Talk:Space hierarchy theorem

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is decidable by definition, so we would have uncountably many languages. But there are only countable many decidable languages, so this result can't be true. It is also not a direct corollary to corollary 1, as with a similar argument
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In the note on step 3: " Execution is limited to 2^f(|x|) steps in order to avoid the case where M does not halt on the input x... That is, the case where M consumes space of only O(f(x)) as required, but runs for infinite time. "
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At cs.SE the proof as given in this article is discussed, and some parts seem to be incorrect or incomplete according to the discussion. Please improve if you are knowledgeable about the subject.
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If M does not halt on input x it does not accept x. The algorithm for deciding L should therefore accept in case more than 2^f(|x|) were made, as M does not accept <M: -->
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I have discussed with others about the validness of corollary 2 and it seems to us that this statement is wrong. For any positive real number
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https://cs.stackexchange.com/questions/104982/proof-of-space-hierarchy-theorem-incompatible-with-linear-speed-up-theorem-for-t/105282
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is not computable and by that not space-constructible for arbitrary real
15: 435: 408: 359: 333: 285: 237: 217: 101:, a collaborative effort to improve the coverage of 441: 421: 393: 345: 319: 271: 223: 163:,10^k is therefore in L, from the definition. 8: 19: 47: 434: 413: 407: 382: 358: 332: 308: 284: 260: 236: 216: 49: 231:there would be a language that is in 7: 95:This article is within the scope of 38:It is of interest to the following 14: 481:Mid-priority mathematics articles 207:Corollary 2- real number argument 115:Knowledge:WikiProject Mathematics 476:Start-Class mathematics articles 118:Template:WikiProject Mathematics 82: 72: 51: 20: 135:This article has been rated as 388: 375: 314: 301: 266: 253: 1: 462:14:11, 15 December 2023 (UTC) 202:22:17, 28 December 2019 (UTC) 109:and see a list of open tasks. 394:{\displaystyle Space(n^{a})} 320:{\displaystyle Space(n^{b})} 272:{\displaystyle Space(n^{a})} 497: 452:I am missing something ? 179:06:31, 1 March 2009 (UTC) 134: 67: 46: 141:project's priority scale 98:WikiProject Mathematics 443: 423: 395: 347: 346:{\displaystyle b<a} 321: 273: 225: 28:This article is rated 444: 424: 422:{\displaystyle n^{a}} 396: 348: 322: 274: 226: 162:,10^k, and <M: --> 433: 406: 357: 331: 283: 235: 215: 121:mathematics articles 439: 419: 391: 353:. Any language in 343: 317: 269: 221: 90:Mathematics portal 34:content assessment 442:{\displaystyle a} 224:{\displaystyle a} 169:comment added by 155: 154: 151: 150: 147: 146: 488: 448: 446: 445: 440: 428: 426: 425: 420: 418: 417: 400: 398: 397: 392: 387: 386: 352: 350: 349: 344: 326: 324: 323: 318: 313: 312: 278: 276: 275: 270: 265: 264: 230: 228: 227: 222: 181: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 496: 495: 491: 490: 489: 487: 486: 485: 466: 465: 431: 430: 409: 404: 403: 378: 355: 354: 329: 328: 304: 281: 280: 256: 233: 232: 213: 212: 209: 187: 164: 120: 117: 114: 111: 110: 88: 81: 61: 32:on Knowledge's 29: 12: 11: 5: 494: 492: 484: 483: 478: 468: 467: 438: 416: 412: 390: 385: 381: 377: 374: 371: 368: 365: 362: 342: 339: 336: 316: 311: 307: 303: 300: 297: 294: 291: 288: 268: 263: 259: 255: 252: 249: 246: 243: 240: 220: 208: 205: 186: 185:Flaw in proof? 183: 153: 152: 149: 148: 145: 144: 133: 127: 126: 124: 107:the discussion 94: 93: 77: 65: 64: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 493: 482: 479: 477: 474: 473: 471: 464: 463: 459: 455: 450: 436: 414: 410: 383: 379: 372: 369: 366: 363: 360: 340: 337: 334: 309: 305: 298: 295: 292: 289: 286: 279:, but not in 261: 257: 250: 247: 244: 241: 238: 218: 206: 204: 203: 199: 195: 192: 184: 182: 180: 176: 172: 168: 159: 142: 138: 132: 129: 128: 125: 108: 104: 100: 99: 91: 85: 80: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 451: 210: 188: 171:132.74.99.86 160: 156: 137:Mid-priority 136: 96: 62:Mid‑priority 40:WikiProjects 165:—Preceding 112:Mathematics 103:mathematics 59:Mathematics 30:Start-class 470:Categories 327:for any 167:unsigned 139:on the 454:JT0202 194:Hermel 36:scale. 458:talk 338:< 198:talk 175:talk 131:Mid 472:: 460:) 449:. 200:) 177:) 456:( 437:a 415:a 411:n 389:) 384:a 380:n 376:( 373:e 370:c 367:a 364:p 361:S 341:a 335:b 315:) 310:b 306:n 302:( 299:e 296:c 293:a 290:p 287:S 267:) 262:a 258:n 254:( 251:e 248:c 245:a 242:p 239:S 219:a 196:( 173:( 143:. 42::

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132.74.99.86
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06:31, 1 March 2009 (UTC)
https://cs.stackexchange.com/questions/104982/proof-of-space-hierarchy-theorem-incompatible-with-linear-speed-up-theorem-for-t/105282
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22:17, 28 December 2019 (UTC)
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14:11, 15 December 2023 (UTC)
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