File size: 66,757 Bytes
6fa4bc9 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 | {
"paper_id": "P91-1008",
"header": {
"generated_with": "S2ORC 1.0.0",
"date_generated": "2023-01-19T09:03:25.607811Z"
},
"title": "DISCOURSE RELATIONS AND DEFEASIBLE KNOWLEDGE*",
"authors": [
{
"first": "Alex",
"middle": [],
"last": "Lascarides",
"suffix": "",
"affiliation": {},
"email": ""
},
{
"first": "Nicholas",
"middle": [],
"last": "Asher",
"suffix": "",
"affiliation": {},
"email": "asher@sygmund@cgs.utexas"
}
],
"year": "",
"venue": null,
"identifiers": {},
"abstract": "This paper presents a formal account of the temporal interpretation of text. The distinct natural interpretations of texts with similar syntax are explained in terms of defeasible rules characterising causal laws and Gricean-style pragmatic maxims. Intuitively compelling patterns of defea,sible entailment that are supported by the logic in which the theory is expressed are shown to underly temporal interpretation. The Problem The temporal interpretation of text involves an account of how the events described are related to each other. These relations follow from the discourse relations that are central to temporal import. 1 Some of these are listed below, where the clause a appears in the text before fl: Narration(a,fl): The event described in fl is a consequence of (but not necessarily caused by) tile event described in a: (1) Max stood up. John greeted him. Elaboration(a,~): The event described in /? contributes to the occurrence of the culmination *This paper is greatly influenced by work reported in (Lascarides & Oberlander, 1991). We would llke to thank Hans Kamp, Michael Morreau and .Ion Oberlander for their significant contributions to the content of this paper. All mistakes are solely our responsibility. t The support of the Science and Engineering Research Council through project number GR/G22077 is gratefully acknowledged. HCRC is supported by the Economic and Social Research Council. 1 Extensive classifications of discourse relations are offered in (Polanyi, 1985), (Scha & Polanyi, 1988) and (Thompson & Mann, 1987). of the event described in a, i.e. fl's event is part of the preparatory phase of a's: 2 (2) The council built the bridge. The architect drew up the plans. Explanation(a, fl): For example the event described in clause fl caused the event described in clause a: (3) Max fell. John pushed him. Background(a, fl): For example the state described in fl is the 'backdrop' or circumstances under which the event in a occurred (so the event and state temporally overlap): (4) Max opened the door. The room was pitch dark.",
"pdf_parse": {
"paper_id": "P91-1008",
"_pdf_hash": "",
"abstract": [
{
"text": "This paper presents a formal account of the temporal interpretation of text. The distinct natural interpretations of texts with similar syntax are explained in terms of defeasible rules characterising causal laws and Gricean-style pragmatic maxims. Intuitively compelling patterns of defea,sible entailment that are supported by the logic in which the theory is expressed are shown to underly temporal interpretation. The Problem The temporal interpretation of text involves an account of how the events described are related to each other. These relations follow from the discourse relations that are central to temporal import. 1 Some of these are listed below, where the clause a appears in the text before fl: Narration(a,fl): The event described in fl is a consequence of (but not necessarily caused by) tile event described in a: (1) Max stood up. John greeted him. Elaboration(a,~): The event described in /? contributes to the occurrence of the culmination *This paper is greatly influenced by work reported in (Lascarides & Oberlander, 1991). We would llke to thank Hans Kamp, Michael Morreau and .Ion Oberlander for their significant contributions to the content of this paper. All mistakes are solely our responsibility. t The support of the Science and Engineering Research Council through project number GR/G22077 is gratefully acknowledged. HCRC is supported by the Economic and Social Research Council. 1 Extensive classifications of discourse relations are offered in (Polanyi, 1985), (Scha & Polanyi, 1988) and (Thompson & Mann, 1987). of the event described in a, i.e. fl's event is part of the preparatory phase of a's: 2 (2) The council built the bridge. The architect drew up the plans. Explanation(a, fl): For example the event described in clause fl caused the event described in clause a: (3) Max fell. John pushed him. Background(a, fl): For example the state described in fl is the 'backdrop' or circumstances under which the event in a occurred (so the event and state temporally overlap): (4) Max opened the door. The room was pitch dark.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Abstract",
"sec_num": null
}
],
"body_text": [
{
"text": "We assume that more than one discourse relation can hold between two sentences; the sickness in (6) describes the circumstances when Max took the aspirin (hence the sentences are related by Background) and also explains why he took the aspirin (hence the sentences are related by Explanation as well).",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "(6) Max took an aspirin. He was sick.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "The sentences in texts (1) and (3) and in (4) and (5) have similar syntax, and therefore similar logical forms. They indicate, therefore, that the constraints on the use of the above discourse relations cannot rely solely on the logical forms of the sentences concerned.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "No theory at present is able to explain the distinct temporal structures of all the above texts. Webber (1988) observes that Kamp & Rohrer (1983) , Partee (1984) , Hinrichs (1986) and Dowty (1986) don't account for the backwards movement of time in (2) and (3). Webber (1988) can account for the backwards movement of time in (2), but her theory is unable to predict that mismatching the descriptive order of events and their temporal order is allowed in some cases (e.g. (2) and (3)) but not in others (e.g. (1), which would be misleading if the situation being described were one where the greeting happened before Max stood up).",
"cite_spans": [
{
"start": 97,
"end": 110,
"text": "Webber (1988)",
"ref_id": "BIBREF22"
},
{
"start": 125,
"end": 145,
"text": "Kamp & Rohrer (1983)",
"ref_id": "BIBREF12"
},
{
"start": 148,
"end": 161,
"text": "Partee (1984)",
"ref_id": null
},
{
"start": 164,
"end": 179,
"text": "Hinrichs (1986)",
"ref_id": null
},
{
"start": 184,
"end": 196,
"text": "Dowty (1986)",
"ref_id": "BIBREF5"
},
{
"start": 262,
"end": 275,
"text": "Webber (1988)",
"ref_id": "BIBREF22"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "Our aim is to characterise the circumstances under which each of the above discourse relations hold, and to explain why texts can invoke different temporal relations in spite of their similar syntax. Dahlgren (1988) represents the difference between (1) and (3) in terms of probabilistic laws describing world knowledge (WK) and linguistic knowledge (LK). Our approach to the problem is generally sympathetic to hers. But Dahlgren's account lacks an underlying theory of inference. Furthermore, it's not clear how a logical consequence relation could be defined upon Dahlgren's representation scheme because the probabilistic laws that need to interact in certain specific ways are not logically related. Unlike Dahlgren (1988) , we will supply an inference regime that drives the interpretation of text.",
"cite_spans": [
{
"start": 200,
"end": 215,
"text": "Dahlgren (1988)",
"ref_id": "BIBREF3"
},
{
"start": 712,
"end": 727,
"text": "Dahlgren (1988)",
"ref_id": "BIBREF3"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "The properties required of an inference mechanism for inferring the causal structure underlying text is discussed in (Lascarides & Oberlander, 1991) . The work presented here builds on this in two ways; first by supplying the required notion of inference, and second by accounting for discourse structure as well as temporal structure.",
"cite_spans": [
{
"start": 117,
"end": 148,
"text": "(Lascarides & Oberlander, 1991)",
"ref_id": "BIBREF15"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "Let us consider texts (1) and (3) on an intuitive level. There is a difference in the relation that typically holds between the events being described. Intuitively, world knowledge (WK) in-eludes a causal 'law' gained from perception and experience that relates falling and pushing: 3",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Temporal Relations and Defeasible Reasoning",
"sec_num": null
},
{
"text": "Connected events el where x falls and e2 where y pushes z are normally such that e2 causes el.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Causal Law 3",
"sec_num": null
},
{
"text": "There is no similar law for standing up and greeting. The above law is a de feasible law. Our claim is that it forms the basis for the distinction between (1) and 3, and that defeasible reasoning underlies the temporal interpretation of text.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Causal Law 3",
"sec_num": null
},
{
"text": "First consider text (1). Intuitively, if there is no temporM information at all gained from WK or syntactic markers (apart from the simple past tense which is the only temporal 'expression' we consider here), then the descriptive order of events provides the only vital clue as to their temporal order, and one assumes that descriptive order matches temporal order. This principle is a re-statement of Grice's (1975) maxim of Manner, where it is suggested that text should be orderly, and it is also motivated by the fact that the author typically describes events in the order in which the protagonist perceives them (cf. Dowty (1986) ). This maxim of interpretation can be captured by the following two laws:",
"cite_spans": [
{
"start": 402,
"end": 416,
"text": "Grice's (1975)",
"ref_id": null
},
{
"start": 623,
"end": 635,
"text": "Dowty (1986)",
"ref_id": "BIBREF5"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Causal Law 3",
"sec_num": null
},
{
"text": "\u2022 Narration Unless there's information to the contrary, clauses a and j3 that are discourse-related are such that Narration(a, ~) holds.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Causal Law 3",
"sec_num": null
},
{
"text": "If Narration(a, fl) holds, and a and fi describe the events el and e2 respectively, then el occurs before e2.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "Narration is defensible and the Axiom for Narration is indefeasible. The idea that Gricean-style pragmatic maxims should be represented as defeasible rules is suggested in (Joshi, Webber & Weischedel (1984) ).",
"cite_spans": [
{
"start": 172,
"end": 206,
"text": "(Joshi, Webber & Weischedel (1984)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "The above rules can be defined in MASH--a logic for defensible reasoning described in (Asher & Morrean, 1991) . We will demonstrate shortly that an intuitively compelling pattern of defensible inference can then underly the interpretation of (1).",
"cite_spans": [
{
"start": 86,
"end": 109,
"text": "(Asher & Morrean, 1991)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "MASH supplies a modal semantics for a language with a default or generic quantifier, and a 3The causal law's index corresponds to the index of the text for which it is relevant. dynamic partial semantics of belief states is built on top of this modal semantics to c~pture intuitively compelling patterns of non-monotonic teasoning. We use a propositional version of MASH here. Defaults are represented as \u00a2 > \u00a2 (read as \"\u00a2 then \u00a2, unless there is information to the contrary\"). The monotonic component of the theory defines a notion of validity ~ that supports axioms such as ~ [:3 We assume a dynamic theory of discourse structure construction in which a discourse structure is built up through the processing of successive clauses in a text. To simplify our exposition, we will assume that the basic constructs of these structures are clauses. 4 Let (4,13) mean that the clause ~ is to be attached to the clause a with a discourse relation, where a is part of the already built up discourse structure. Let me(a) be a term that refers to the main eventuality described by a (e.g. me(Max stood up) is the event of Max standing up). 5 Then Narration and the axiom on Narration are represented in MASH as follows (cl -~ e.~ means \"el wholly occurs before e2\"):",
"cite_spans": [
{
"start": 578,
"end": 581,
"text": "[:3",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "(\u00a2 --* \u00a2) ~ ((X > \u00a2) --~ (X > \u00a2)).",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "4The theory should extend naturally to an account where the basic constructs are segments of text; the approach adopted here is explored extensively in Asher (forthcoming).",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "5me(c~) is formally defined in Lascarides & Asher (1991) in a way that agrees with intuitions.",
"cite_spans": [
{
"start": 31,
"end": 56,
"text": "Lascarides & Asher (1991)",
"ref_id": "BIBREF14"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "\u2022 Axiom for Narration",
"sec_num": null
},
{
"text": "\u2022 Axiom on Narration",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "(or, ~) > Narration(c~,~3)",
"sec_num": null
},
{
"text": "We assume that in interpreting text the reader believes all LK and WK (and therefore believes Narration and its axiom), the laws of logic, and the sentences in the text. The sentences in 1 In words, (7) invokes two discourse referents el and ~1 (which behave like deictic expressions), where el is an event of Max standing up, tl is a point of time earlier than now and et occurs at it. (8) is similar save that the event e2 describes John greeting Max. 7and 8place no conditions on the relative temporal order between et and e2. These are derived at a higher level of analysis than sentential semantics by using defensible reasoning.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "Suppose that the reader also believes that the clauses in text (1) are related by some discourse relation, as they must be for the text to be coherent. Then the reader's beliefs also include (7, 8). The natural interpretation of (1) is derived by calculating the common sense entailments from the reader's belief state. Given the assumptions on this state that we have just described, the antecedent to Narration is verified, and so by Defensible Modus Ponens, Narration(7, 8) is inferred.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "Since the belief states in MASH support modal closure, this result and the Axiom on Narration entail that the reader believes the main eventuality of (7), namely el, precedes the main eventuality of (8), namely e2. So the intuitive discourse structure and temporal interpretation of (1) is derived by exploiting defeasible knowledge that expresses a Gricean-style pragmatic maxim.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "But the analysis of (1) is satisfactory only if the same technique of exploiting defeasible rules can be used to obtain the appropriate natural interpretation of (3), which is different from (1) in spite of their similar syntax.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "eFor the sake of simplicity we ignore the problem of resolving the NP anaphora in (8). The truth definitions of (7) and (8) are llke those given in DRT save that they are evaluated with respect to a possible world index since MASH is modal.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "(3) a.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "Max fell.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "r~ (Na,','atio,~(~, ~) --, me(~) ~ me(Z))",
"sec_num": null
},
{
"text": "John pushed him.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "As we mentioned before, Causal Law 3 will provide the basis for the distinct interpretations of (1) and (3). The clauses in (3) must be related by a discourse relation for the text to be coherent, and therefore given the meanings of the discourse relations, the events described must be connected somehow. Therefore when considering the domain of interpreting text, one can re-state the above causal law as follows: 7",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Causal Law 3 Clauses a and/3 that are discourse-related where a describes an event el of x falling and/3 describes an event e~ of y pushing x are normally such that e2 causes el.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The representation of this in MASH is:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Causal Law 3 (a,/3)^f.n(x, me(a))^push(y, x, me(/3)) > ca~se(m~(~), me(a))",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "This represents a mixture of WK and linguistic knowledge (LK), for it asserts that given the sentences are discourse-related somehow, and given the kinds of events that are described by these sentences, the second event described caused the first, if things are normal.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The logical forms for (3a) and (3b) are the same as (7) and (8), save that standup and greet are replaced respectively with fall and push.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Upon interpreting (3), the reader believes all defeasible wK and LK together with (3a), (3b) and (3a, 3b). Hence the antecedents to two defeasible laws are satisfied: Narration and Causal Law 3. Moreover, the antecedent of Law 3 entails that of Narration, and the laws conflict because of the axiom on Narration and the axiom that causes precede effects:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "\u2022 Causes Precede Effects [] (Vele2)(cause(el, e2) ~ ~e2 -~ el)",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The result is a 'Complex' Penguin Principle: it is complex because the consequents of the two defeasible laws are not ~ and -~ff, but instead the laws conflict in virtue of the above axioms. MASH supports the more complex Penguin Principle:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": ";'This law may seem very 'specific'. It could potentially be generalised, perhaps by re-stating el as x moving and e2 as y applying a force to x. For the sake of brevity we ignore this generalisation.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "\u2022 Complex Penguin Principle o(\u00a2 \u00a2),\u00a2 > x,\u00a2 > \u00a2, o(x 0), [] (\u00a2 \u00a2 but not: [] (\u00a2 --* \u00a2), \u00a2 > X, \u00a2 > (, o (x 0), n (\u00a2 -. \u00a2 x",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Therefore there is a defeasible inference that the pushing caused the falling from the premises, as required.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The use of the discourse relation Explanation is characterised by the following rule:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "\u2022 Explanation (a, A >",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Explanation (a, jr) In words, if a and f~ are discourse-related and the event described in/3 caused the event described in a, then Explanation(a, ~) normally holds. Furthermore, Explanation imposes a certain temporal structure on the events described so that if is a causal explanation of a then fPs event doesn't precede a's:",
"cite_spans": [
{
"start": 12,
"end": 19,
"text": "(a, jr)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "\u2022 Axiom on Explanation",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The antecedent to Narration is verified by the reader's beliefs, and given the results of the Complex Penguin Principle above, the antecedent to Explanation is also verified. Moreover, the antecedent to Explanation entails that of Narration, and these laws conflict because of the above axioms. So there is another complex Penguin Principle, from which Explanation(3a, 3b) is inferred.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "[] (Explanation(a,/3) -~ -~me(a ) -~ rne(/3 ) )",
"sec_num": null
},
{
"text": "The second application of the Penguin Principle in the above used the results of the first, but in nonmonotonic reasoning one must be wary of dividing theories into 'subtheories' in this way because adding premises to nonmonotonic deductions does not always preserve conclusions, making it necessary to look at the theory as a whole. (Lascarides & Asher, 1991) shows that the predicates involved in the above deduction are sufficiently independent that in MASH one can indeed divide the above into two applications of the Penguin Principle to yield inferences from the theory as a whole. Thus our intuitions about the kind of reasoning used in analysing (3) are supported in the logic. We call this double application of the Penguin Principle where the second application uses the results of the first the Cascaded Penguin Principle. s 8On a general level, MASH is designed so that the con-",
"cite_spans": [
{
"start": 334,
"end": 360,
"text": "(Lascarides & Asher, 1991)",
"ref_id": "BIBREF14"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "[] (Explanation(a,/3) -~ -~me(a ) -~ rne(/3 ) )",
"sec_num": null
},
{
"text": "Certain constraints are imposed on discourse structure: Let R be Explanation or Elaboration;",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Structures",
"sec_num": null
},
{
"text": "then the current sentence can be discourse related only to the previous sentence a, to a sentence fl such that R(fl, a), or to a sentence 7 such that R(7, fl) and R(~, a). This is a simpler version of the definition for possible attachment sites in Asher (forthcoming). Pictorially, the possible sites for discourse attachment in the example structure below are those marked open:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Structures",
"sec_num": null
},
{
"text": "Open Explana~ l anati\u00b0n Closed Open Narration Explanation/// ~xplanation Closed ~ Open",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Structures",
"sec_num": null
},
{
"text": "There are structural similarities between our notion of openness and Polanyi's (1985) . The above constraints on attachment explain the awkwardness of text (9a-f) because (9c) is not available to (gf) for discourse attachment. f. ?He boned the salmon with great expertise.",
"cite_spans": [
{
"start": 69,
"end": 85,
"text": "Polanyi's (1985)",
"ref_id": "BIBREF18"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "Narrati on",
"sec_num": null
},
{
"text": "According to the constraint on attachment, the only available sentence for attachment if one were to add a sentence to (1) is John greeted him, whereas in (3), both sentences are available. Thus although the sentences in (1) and (3) were assigned similar structural semantics, they have very different discourse structures. The events they flict between defeasible laws whose antecedents axe such that one of them entails the other is resolvable. Thus unwanted irresolvable conflicts can be avoided. describe also have different causal structures. These distinctions have been characterised in terms of defeasible rules representing causal laws and pragmatic maxims. We now use this strategy to analyse the other texts we mentioned above.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Narrati on",
"sec_num": null
},
{
"text": "Consider text (2).",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Elaboration",
"sec_num": null
},
{
"text": "(2) a.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Elaboration",
"sec_num": null
},
{
"text": "The council built the bridge.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Elaboration",
"sec_num": null
},
{
"text": "The architect drew up the plans.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "We conclude Elaboration(2a, 2b) in a very similar way to example (3), save that we replace cause(me(~), me(a)) in the appropriate defensible rules with prep(me(~), me(a)), which means that rne(~) is part of the preparatory phase of me(a). In Law 2 below, Info(a,~) is a gloss for \"the event described in a is the council building the bridge, and the event described in fl is the architect drawing up the plans\", and the law represents the knowledge that drawing plans and building the bridge, if connected, are normally such that the former is in the preparatory phase of the latter: ^ prep( e( ), me(a) Info(a, > prep(me(Z) , )",
"cite_spans": [],
"ref_spans": [
{
"start": 584,
"end": 603,
"text": "^ prep( e( ), me(a)",
"ref_id": null
},
{
"start": 604,
"end": 624,
"text": "Info(a, > prep(me(Z)",
"ref_id": null
}
],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "\u2022 Elaboration (a,",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The inference pattern is a Cascaded Penguin Principle again. The two resolvable conflicts are Law 2 and Narration and Elaboration and Narration.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Intuitively, the clauses in (4) are related by Background.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "(4) Max opened the door. The room was pitch dark.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "The appropriate reader's belief state verifies the antecedent of Narration. In addition, we claim that the following laws hold:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "\u2022 States Overlap Background(a, overlap(me(a) , me(~) ) )",
"cite_spans": [],
"ref_spans": [
{
"start": 17,
"end": 45,
"text": "Background(a, overlap(me(a)",
"ref_id": null
}
],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "States Overlap ensures that when attached clauses describe an event and state and we have no knowledge about how the event and state are connected, gained from WK or syntactic markers like because and therefore, we assume that they temporally overlap. This law can be seen as a manifestation of Grice's Maxim of Relevance as suggested in (Lascarides, 1990) : if the start of the state is not indicated by stating what caused it or by introducing an appropriate syntactic marker, then by Grice's Maxim of Relevance the starting point, and is irrelevant to the situation being described.",
"cite_spans": [
{
"start": 338,
"end": 356,
"text": "(Lascarides, 1990)",
"ref_id": "BIBREF13"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "So the start of the state must have occurred before the situation that the text is concerned with occurs. As before, we assume that unless there is information to the contrary, the descriptive order of eventualities marks the order of their discovery. This together with the above assumption about where the state starts entail that unless there's information to the contrary, the state temporally overlaps events or states that were described previously, as asserted in States Overlap.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "We assume that the logical form of the second clause in 4 ",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Background",
"sec_num": null
},
{
"text": "(5) has similar syntax to (4), and yet unlike (4) the event causes the state and the discourse relation is Result.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Result",
"sec_num": null
},
{
"text": "(5) a. Max switched off the light.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Result",
"sec_num": null
},
{
"text": "The room was pitch dark.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Let Info(a,fl) be a gloss for \"me(a) is Max switching off the light and me(fl) is the room being dark\". So by the stative classification of dark, Info(a, fl) entails state(me(~)). Then Law 5 reflects the knowledge that the room being dark and switching off the light, if connected, are normally such that the event causes the state: 9",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "\u2022 Causal Law 5 (a,/7) A Info(a,~) > cause(me(a), me(/7))",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "The use of the discourse relation of Result is characterised by the following: The reader's beliefs in analysing 5 Result(ha, 5b) and Narration(ha, hb) are inferred. Note that thanks to the axioms on Background and Result and the inconsistency of overlap (el, e~) and el -~ e2, these discourse relations are inconsistent. This captures the intuition that if a causes b, then b could not have been the case when a happened. In particular, if Max switching off the light caused the darkness, then the room could not have been dark when Max switched off the light.",
"cite_spans": [
{
"start": 115,
"end": 125,
"text": "Result(ha,",
"ref_id": null
},
{
"start": 126,
"end": 129,
"text": "5b)",
"ref_id": null
},
{
"start": 134,
"end": 151,
"text": "Narration(ha, hb)",
"ref_id": null
},
{
"start": 255,
"end": 263,
"text": "(el, e~)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "Consider text (9a-e): (9) a.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Discourse Popping",
"sec_num": null
},
{
"text": "Guy experienced a lovely evening last night.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Discourse Popping",
"sec_num": null
},
{
"text": "He had a fantastic meal.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "9For the sake of simplicity, we ignore the problem of inferring that the light is in the room. ",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "b.",
"sec_num": null
},
{
"text": "We study the attachment of (9e) to the preceding text in detail. Given the concept of openness introduced above, the open clauses are (9d), (95) and (9a). So by the assumptions on text processing, the reader believes (9d, 9e), (9b, 9e) and (9a, 9e). (9d, 9e) verifies the antecedent to Narration, but intuitively, (9d) is not related to (9e) at all. The reason for this can be explained in words as follows:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Narration lots Of cheese",
"sec_num": null
},
{
"text": "\u2022 (9d) and (9e) don't form a narrative because:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Narration lots Of cheese",
"sec_num": null
},
{
"text": "-Winning a dance competition is normally not part Of a meal; -So (9e) doesn't normally elaborate (9b); -But since (9d) elaborates (95), (9e) can normally form a narrative with (9d) only if (9e) also elaborates (9b). 9e) . We assume that believing (9d, 9e) and failing to support any discourse relation between (9d) and (9e) is incoherent. So (9d,9e) cannot be believed. Thus the Nixon Diamond provides the key to discourse 'popping', for (9e) must be related to one of the remaining open clauses; i.e. (95) or (9a). In fact by making use of the knowledge that winning a dance competition is normally part of experiencing a lovely evening if these things are connected, Elaboration(9a, 9e) and Narration(9b, 9e) follow as before, in agreement with intuitions.",
"cite_spans": [
{
"start": 216,
"end": 219,
"text": "9e)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "Narration lots Of cheese",
"sec_num": null
},
{
"text": "We have proposed that distinct natural interpretations of texts with similar syntax can be explained in terms of defeasible rules that represent causal laws and Gricean-style pragmatic maxims. The distinct discourse relations and event relations arose from intuitively compelling patterns of defeasible entailment. The Penguin Principle captures the intuition that a reader never ignores information salient in text that is relevant to calculating temporal and discourse structure. The Nixon Diamond provided the key to 'popping' from subordinate discourse structure.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Conclusion",
"sec_num": null
},
{
"text": "We have investigated the analysis of texts involving only the simple past tense, with no other temporal markers present. Lascarides & Asher (1991) show that the strategy pursued here can be applied to the pluperfect as well. Future work will involve extending the theory to handle texts that feature temporal connectives and adverbials.",
"cite_spans": [
{
"start": 121,
"end": 146,
"text": "Lascarides & Asher (1991)",
"ref_id": "BIBREF14"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "Conclusion",
"sec_num": null
},
{
"text": "2We assumeMoens and Steedman's (1988) tripartite structure of events, where an event consists of a preparatory phase, a culmination and a consequent phase.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
}
],
"back_matter": [],
"bib_entries": {
"BIBREF0": {
"ref_id": "b0",
"title": "Abstract Objects, Semantics and Anaphora",
"authors": [
{
"first": "Nicholas",
"middle": [],
"last": "Asher",
"suffix": ""
}
],
"year": null,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Asher, Nicholas [forthcoming] Abstract Objects, Semantics and Anaphora.",
"links": null
},
"BIBREF2": {
"ref_id": "b2",
"title": "The Generic Book, Proceedings to JELIA90",
"authors": [],
"year": null,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Common Sense Entailment: A Modal Theory of Nonmonotonic Reasoning, in Carlson, Greg & Pelletier, Jeff (eds.) The Generic Book, Proceed- ings to JELIA90, University of Chicago Press.",
"links": null
},
"BIBREF3": {
"ref_id": "b3",
"title": "Naive Semantics for Natural Language Understanding",
"authors": [
{
"first": "Kathleen",
"middle": [],
"last": "Dahlgren",
"suffix": ""
}
],
"year": 1988,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Dahlgren, Kathleen [1988] Naive Semantics for Natural Language Understanding, Kluwer Aca- demic Publishers;",
"links": null
},
"BIBREF5": {
"ref_id": "b5",
"title": "The Effects of Aspeetual Class on the Temporal Structure of Discourse: Semantics or Pragmatics? Linguistics and Philosophy",
"authors": [
{
"first": "David",
"middle": [],
"last": "Dowty",
"suffix": ""
}
],
"year": 1986,
"venue": "",
"volume": "9",
"issue": "",
"pages": "37--61",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Dowty, David [1986] The Effects of Aspeetual Class on the Temporal Structure of Discourse: Se- mantics or Pragmatics? Linguistics and Philoso- phy, 9, 37-61.",
"links": null
},
"BIBREF7": {
"ref_id": "b7",
"title": "Speech Acts",
"authors": [],
"year": null,
"venue": "",
"volume": "3",
"issue": "",
"pages": "41--58",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "In Cole, P. and Morgan, J. L. (eds.) Syntaz and Semantics, Volume 3: Speech Acts, pp41-58. New York: Academic Press.",
"links": null
},
"BIBREF8": {
"ref_id": "b8",
"title": "Temporal Anaphora in Discourses of English. Linguistics and Philosophy",
"authors": [
{
"first": "Erhard",
"middle": [],
"last": "Itinrichs",
"suffix": ""
}
],
"year": 1986,
"venue": "",
"volume": "9",
"issue": "",
"pages": "63--82",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Itinrichs, Erhard [1986] Temporal Anaphora in Discourses of English. Linguistics and Philoso- phy, 9, 63-82.",
"links": null
},
"BIBREF10": {
"ref_id": "b10",
"title": "Default Reasoning in Interaction",
"authors": [
{
"first": "Ralph",
"middle": [],
"last": "Weischedel",
"suffix": ""
}
],
"year": 1984,
"venue": "Proceedings of the Non-Monotonic Reasoning Workshop, AAAI",
"volume": "",
"issue": "",
"pages": "144--150",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Weischedel, Ralph [1984] Default Reasoning in Interaction. In Proceedings of the Non-Monotonic Reasoning Workshop, AAAI, New York, October, 1984, 144-150.",
"links": null
},
"BIBREF11": {
"ref_id": "b11",
"title": "A Theory of Truth and Semantic Representation",
"authors": [
{
"first": "Hans",
"middle": [],
"last": "Kamp",
"suffix": ""
}
],
"year": 1981,
"venue": "Formal Methods in the Study of Language",
"volume": "136",
"issue": "",
"pages": "277--322",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Kamp, Hans [1981] A Theory of Truth and Se- mantic Representation. In Groenendijk, J. A. G., Janssen, T. M. V. and Stokhof, M. B. J. (eds.) Formal Methods in the Study of Language, Vol- ume 136, pp277-322. Amsterdam: Mathematical Centre Tracts.",
"links": null
},
"BIBREF12": {
"ref_id": "b12",
"title": "Tense in Texts",
"authors": [
{
"first": "Hans",
"middle": [
"&"
],
"last": "Kamp",
"suffix": ""
},
{
"first": "Christian",
"middle": [],
"last": "Rohrer",
"suffix": ""
}
],
"year": 1983,
"venue": "Meaning, Use and Interpretation of Language",
"volume": "",
"issue": "",
"pages": "250--269",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Kamp, Hans & Rohrer, Christian [1983] Tense in Texts. In Bauerle, R., Schwarze, C. and yon Stechow, A. (eds.) Meaning, Use and Interpreta- tion of Language, pp250-269. Berlin: de Gruyter.",
"links": null
},
"BIBREF13": {
"ref_id": "b13",
"title": "Research Report No. HCRC/RP-8, Human Communication Research Centre",
"authors": [
{
"first": "Alex",
"middle": [],
"last": "Lascarides",
"suffix": ""
}
],
"year": 1990,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Lascarides, Alex [1990] Knowledge, Causality and Temporal Representation. Research Report No. HCRC/RP-8, Human Communication Re- search Centre, University of Edinburgh, Edin- burgh, June, 1990.",
"links": null
},
"BIBREF14": {
"ref_id": "b14",
"title": "Discourse Relations and Common Sense Entailment, DYANA deliverable 2.5b, available from Centre for Cognitive Science",
"authors": [
{
"first": "Alex",
"middle": [
"&"
],
"last": "Lascarides",
"suffix": ""
},
{
"first": "Nicholas",
"middle": [],
"last": "Asher",
"suffix": ""
}
],
"year": 1991,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Lascarides, Alex & Asher, Nicholas [1991] Dis- course Relations and Common Sense Entailment, DYANA deliverable 2.5b, available from Centre for Cognitive Science, University of Edinburgh.",
"links": null
},
"BIBREF15": {
"ref_id": "b15",
"title": "Temporal Coherence and Defeasible Knowledge",
"authors": [
{
"first": "Alex",
"middle": [
"&"
],
"last": "Lascarides",
"suffix": ""
},
{
"first": "Jon",
"middle": [],
"last": "Oberlander",
"suffix": ""
}
],
"year": 1991,
"venue": "Proceedings to the Workshop on Discourse Coherence",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Lascarides, Alex & Oberlander, Jon [1991] Tem- poral Coherence and Defeasible Knowledge. In Proceedings to the Workshop on Discourse Co- herence, Edinburgh, April 1991.",
"links": null
},
"BIBREF18": {
"ref_id": "b18",
"title": "Papers from the General Session at the Twenty-First Regional Meeting of the Chicago Linguistics Society",
"authors": [
{
"first": "Livia",
"middle": [],
"last": "Polanyi",
"suffix": ""
}
],
"year": 1985,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Polanyi, Livia [1985] A Theory of Discourse Structure and Discourse Coherence. In Eilfort, W. H., Kroeber, P. D. and Peterson, K. L. (eds.) Papers from the General Session at the Twenty- First Regional Meeting of the Chicago Linguistics Society, Chicago, April 25-27, 1985.",
"links": null
},
"BIBREF19": {
"ref_id": "b19",
"title": "An Augmented Context Free Grammar",
"authors": [
{
"first": "Remko",
"middle": [
"&"
],
"last": "Scha",
"suffix": ""
},
{
"first": "Livia",
"middle": [],
"last": "Polanyi",
"suffix": ""
}
],
"year": 1988,
"venue": "Proceedings of the 121h International Conference on Computational Linguistics and the 24th Annual Meeting of the Association for Computalional Linguistics",
"volume": "",
"issue": "",
"pages": "573--577",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Scha, Remko & Polanyi, Livia [1988] An Aug- mented Context Free Grammar. In Proceedings of the 121h International Conference on Compu- tational Linguistics and the 24th Annual Meeting of the Association for Computalional Linguistics, Budapest, Hungary, 22-27 August, 1988, 573-577.",
"links": null
},
"BIBREF21": {
"ref_id": "b21",
"title": "Rhetorical Structure Theory: A Framework for the Analysis of Texts",
"authors": [],
"year": null,
"venue": "International Pragmaties Association Papers in Pragmatics",
"volume": "1",
"issue": "",
"pages": "79--105",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Rhetorical Structure Theory: A Frame- work for the Analysis of Texts. International Pragmaties Association Papers in Pragmatics, 1, 79-105.",
"links": null
},
"BIBREF22": {
"ref_id": "b22",
"title": "Tense as Discourse Anaphor. Computational Linguistics",
"authors": [
{
"first": "Bonnie",
"middle": [],
"last": "Webber",
"suffix": ""
}
],
"year": 1988,
"venue": "",
"volume": "14",
"issue": "",
"pages": "61--73",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Webber, Bonnie [1988] Tense as Discourse Anaphor. Computational Linguistics, 14, 61-73.",
"links": null
}
},
"ref_entries": {
"FIGREF0": {
"uris": null,
"text": "are represented in a DnT-type framework as follows: 6 (7) [e1,~1][~1 <now, hold(el,Q),s~andup(rn, el)] (8) [~, t~][t2< now, hold(~2, t2),gr~t(j, m, ~2)]",
"type_str": "figure",
"num": null
},
"FIGREF3": {
"uris": null,
"text": "(a,~) --. me(a) ~ me(fl))",
"type_str": "figure",
"num": null
},
"TABREF5": {
"html": null,
"num": null,
"type_str": "table",
"text": "Thcse intuitions can be formalised, where Info(a, fl) is a. gloss for \"me(a) is having a meal and me(fl)",
"content": "<table><tr><td colspan=\"3\">\u2022 Defeaslbly Necessary Test for</td></tr><tr><td colspan=\"2\">Elaboration</td><td/></tr><tr><td>(a,</td><td>^</td><td>></td></tr><tr><td/><td>-~ Elaboration( a, fl)</td><td/></tr><tr><td colspan=\"3\">\u2022 Constraint on Narration</td></tr><tr><td colspan=\"3\">Elaboration((~, fll )A-~Eiaboration( a, f12 ) ></td></tr><tr><td/><td>-~ N arration(~t , ~2 )</td><td/></tr><tr><td colspan=\"3\">The result is a 'Nixon Polygon'. There is irre-</td></tr><tr><td colspan=\"3\">solvable conflict between Narration and the Con-</td></tr><tr><td colspan=\"3\">straint on Narration because their antecedents are</td></tr><tr><td colspan=\"2\">not logically related:</td><td/></tr><tr><td/><td colspan=\"2\">Narration(9d, 9e)</td></tr><tr><td colspan=\"2\">-~Elaboration(9b, 9e)</td><td/></tr><tr><td colspan=\"2\">Elaboration(9b, 9e)</td><td/></tr><tr><td/><td>l</td><td>(9d,De)</td></tr><tr><td/><td>(9d, 9e)</td><td/></tr><tr><td colspan=\"2\">-~prep(me(9b, 9e)) Elaboration(~</td><td/></tr><tr><td/><td/><td>(9d, 9e)</td></tr><tr><td/><td/><td>Info(9b, 9e)</td></tr><tr><td/><td/><td>Elaboration(9b, 9d)</td></tr><tr><td colspan=\"3\">The above in MASH yields ]i~Narration(9d, 9e)</td></tr><tr><td>and</td><td/><td/></tr><tr><td>is winning a dance competition\":</td><td/><td/></tr><tr><td>* Law 9</td><td/><td/></tr><tr><td>(a, ^ I fo( , Z) > prep(me( ), me(.))</td><td/><td/></tr></table>"
}
}
}
} |