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Talk:Elementary class

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arguably illustrate the concept of reduct better than they do the concept of elementary class. I would be inclined to leave things stand as they are. If no one has any more concrete proposal I'll remove the tags suggesting the merge at some point.
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I now see it's a bit terse. Can you rewrite it to make it clearer? Otherwise I will think about it. (Or is it just a typographic problem? With my fonts and settings the first τ looks like a very small capital T, and the second
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are covered unsystematically, with unnecessary duplications, and with many inconsistencies even within each of the two subjects. I would like to hear other people's opinions on this. --
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I think merging this article with the pseudoelementary class article, and covering both algebra and logic, would be an improvement. — Carl
97: 58: 340:, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section. 173:, which was started by Prof. Pratt. Unfortunately, this is an example of a general problem. Currently the common foundations of 33: 220:. The notions of elementary class and reduct are orthogonal, and the several examples of pseudoelementary classes in 283:"Otherwise the infinite σ-structures would be precisely those which satisfy a certain first-order sentence τ." 250:
What is Tau? is that meant to be capital-T from the example? I don't see where Tau is introduced or defined.
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In the section on "An elementary, basic pseudoelementary class that is not basic elementary" section.
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consisting of a single sentence. Towards a contradiction, we assume that this is the case, and that
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on Knowledge. If you would like to participate, please visit the project page, where you can join
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putting some work into this article I realised that there is also an excellent article on
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Last edited at 14:59, 13 November 2007 (UTC). Substituted at 02:02, 5 May 2016 (UTC)
337: 198: 174: 102: 79: 354: 319: 259: 234: 203: 185: 194: 217: 281:={τ}, so τ is this sentence. This is what happens in the sentence 15: 332: 292: 101:, a collaborative effort to improve the coverage of 302: 336:, and are posted here for posterity. Following 295: 212:An equally good case could be made for merging 330:The comment(s) below were originally left at 8: 19: 47: 291: 293: 49: 158:Overlap with pseudoelementary classes 7: 95:This article is within the scope of 310:looks like a proper tau in TeX.) -- 38:It is of interest to the following 14: 380:Mid-priority mathematics articles 338:several discussions in past years 115:Knowledge:WikiProject Mathematics 375:Start-Class mathematics articles 118:Template:WikiProject Mathematics 82: 72: 51: 20: 135:This article has been rated as 333:Talk:Elementary class/Comments 1: 355:14:59, 13 November 2007 (UTC) 273:were axiomatised by a theory 260:22:16, 30 December 2007 (UTC) 204:20:58, 13 November 2007 (UTC) 186:14:55, 13 November 2007 (UTC) 109:and see a list of open tasks. 269:were basic elementary, then 169:, from the point of view of 320:16:27, 1 January 2008 (UTC) 235:15:36, 18 August 2009 (UTC) 396: 345: 303:{\displaystyle \;\!\tau } 134: 67: 46: 167:pseudoelementary classes 141:project's priority scale 98:WikiProject Mathematics 348:pseudoelementary class 304: 222:pseudoelementary class 214:pseudoelementary class 28:This article is rated 305: 290: 121:mathematics articles 326:Assessment comment 300: 296: 294: 90:Mathematics portal 34:content assessment 360: 359: 202: 179:universal algebra 171:universal algebra 155: 154: 151: 150: 147: 146: 387: 343: 342: 335: 309: 307: 306: 301: 192: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 395: 394: 390: 389: 388: 386: 385: 384: 365: 364: 331: 328: 288: 287: 245: 160: 120: 117: 114: 111: 110: 88: 81: 61: 32:on Knowledge's 29: 12: 11: 5: 393: 391: 383: 382: 377: 367: 366: 358: 357: 327: 324: 323: 322: 299: 244: 241: 240: 239: 238: 237: 207: 206: 159: 156: 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: 392: 381: 378: 376: 373: 372: 370: 363: 356: 353: 349: 344: 341: 339: 334: 325: 321: 317: 313: 297: 284: 280: 276: 272: 268: 264: 263: 262: 261: 257: 253: 248: 242: 236: 232: 228: 227:Vaughan Pratt 223: 219: 215: 211: 210: 209: 208: 205: 200: 196: 190: 189: 188: 187: 184: 180: 176: 172: 168: 164: 157: 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: 361: 329: 282: 278: 274: 270: 266: 249: 246: 175:model theory 162: 161: 137:Mid-priority 136: 96: 62:Mid‑priority 40:WikiProjects 346:Merge with 112:Mathematics 103:mathematics 59:Mathematics 30:Start-class 369:Categories 352:Hans Adler 312:Hans Adler 252:Zero sharp 183:Hans Adler 243:Question 177:and of 139:on the 218:reduct 36:scale. 216:with 163:After 350:? -- 316:talk 256:talk 231:talk 199:talk 265:If 195:CBM 131:Mid 371:: 318:) 298:τ 258:) 233:) 225:-- 197:· 314:( 279:T 275:T 271:K 267:K 254:( 229:( 201:) 193:( 143:. 42::

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mathematics
the discussion
Mid
project's priority scale
pseudoelementary classes
universal algebra
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universal algebra
Hans Adler
14:55, 13 November 2007 (UTC)
CBM
talk
20:58, 13 November 2007 (UTC)
pseudoelementary class
reduct
pseudoelementary class
Vaughan Pratt
talk
15:36, 18 August 2009 (UTC)
Zero sharp
talk

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