File size: 52,803 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 | {
"paper_id": "P87-1032",
"header": {
"generated_with": "S2ORC 1.0.0",
"date_generated": "2023-01-19T09:13:15.397039Z"
},
"title": "",
"authors": [
{
"first": "Harry",
"middle": [
"H"
],
"last": "Porter",
"suffix": "",
"affiliation": {
"laboratory": "",
"institution": "III Oregon Graduate Center",
"location": {
"addrLine": "19600 N.W. Von Neumann Dr. Beaverton Oregon",
"postCode": "97008-1999"
}
},
"email": ""
}
],
"year": "",
"venue": null,
"identifiers": {},
"abstract": "Hassan Ait-Kaci introduced the #/-term, an informational structure resembling featurebased functional structures but which also includes taxonomic inheritance (Ait-Kaci, 1984). We describe e-terms and how they have been incorporated into the Logic Grammar formalism. The result, which we call Inheritance Grammar, is a proper superset of DCG and includes many features of PATR-II. Its taxonomic reasoning facilitates semantic type-class reasoning during grammatical analysis.",
"pdf_parse": {
"paper_id": "P87-1032",
"_pdf_hash": "",
"abstract": [
{
"text": "Hassan Ait-Kaci introduced the #/-term, an informational structure resembling featurebased functional structures but which also includes taxonomic inheritance (Ait-Kaci, 1984). We describe e-terms and how they have been incorporated into the Logic Grammar formalism. The result, which we call Inheritance Grammar, is a proper superset of DCG and includes many features of PATR-II. Its taxonomic reasoning facilitates semantic type-class reasoning during grammatical analysis.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "Abstract",
"sec_num": null
}
],
"body_text": [
{
"text": "The Inheritance Grammar (IG) formalism is an extension of Hassan Ait-Kaci's work on #/terms (Ait-Kaci, 1984; Ait-Kaci and Nasr, 1986) . A e-term is an informational structure similar to both the feature structure of PATR-II (Shieber, 1985; Shieber, et al, 1986) and the first-order term of logic, e-terms are ordered by subsumption and form a lattice in which unification of #/-terms amounts to greatest lower bounds (GLB, [-']) . In Inheritance Grammar, #/terms are incorporated into a computational paradigm similar to the Definite Clause Grammar (DCG) formalism (Pereira and Warren, 1980) . Unlike feature structures and first-order terms, the atomic symbols of #/-terms are ordered in an IS-A taxonomy, a distinction that is useful in performing semantic type-class reasoning during grammatical analysis. We begin by discussing this ordering.",
"cite_spans": [
{
"start": 92,
"end": 108,
"text": "(Ait-Kaci, 1984;",
"ref_id": null
},
{
"start": 109,
"end": 133,
"text": "Ait-Kaci and Nasr, 1986)",
"ref_id": null
},
{
"start": 224,
"end": 239,
"text": "(Shieber, 1985;",
"ref_id": "BIBREF16"
},
{
"start": 240,
"end": 261,
"text": "Shieber, et al, 1986)",
"ref_id": "BIBREF17"
},
{
"start": 417,
"end": 428,
"text": "(GLB, [-'])",
"ref_id": null
},
{
"start": 565,
"end": 591,
"text": "(Pereira and Warren, 1980)",
"ref_id": "BIBREF12"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "INTRODUCTION",
"sec_num": null
},
{
"text": "Like other grammar formalisms using feature-based functional structures, we will assume a fixed set of symbol8 called the signature. These symbols are atomic values used to represent lexical, syntactic and semantic categories and other feature values. In many formalisms (e.g. DCG and PATR-II), equality is the only operation for symbols; in IG symbols are related in an IS-A hierarchy. These relationships are indicated in the grammar using statements such as1:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "THE IS-A RELATION AMONG FEATURE VALUES",
"sec_num": null
},
{
"text": "boy < masculineObject. girl < feminineObject. man < masculineObject. woman < feminineObJect. {boy, girl} < child. {man, woman} < adult. {child, adult} < human.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "THE IS-A RELATION AMONG FEATURE VALUES",
"sec_num": null
},
{
"text": "The symbol < can be read as \"is a\" and the notation {a,,... ,an}<b is an abbreviation for al<b, \u2022 \u2022 \u2022 ,an<b. The grammar writer need not distinguish between instances and classes, or between syntactic and semantic categories when the hierarchy is specified. Such distinctions are only determined by how the symbols are used in the grammar. Note that this example ordering exhibits multiple inheritance: feminineObjeers are not necessarily humans and humans are not necessarily feminine0b-",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "THE IS-A RELATION AMONG FEATURE VALUES",
"sec_num": null
},
{
"text": "Jeers, yet a girl is both a human and a feminineObj ect.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "THE IS-A RELATION AMONG FEATURE VALUES",
"sec_num": null
},
{
"text": "Computation of LUB (t_ J) and GLB (['7) in arbitrary partial orders is problematic. In IG, the grammar writer specifies an arbitrary ordering which the rule execution system automatically embeds in a lattice by the addition of newly created symbols (Maier, 1980) . Symbols may be thought of as standing for conceptual sets or semantic types and the IS-A relationship can be thought of as set I Symbols appearing in the grammar but not in the inclusion. Finding the GLB-i.e. unification of symbols-then amounts to set intersection. For the partial order specified above, two new symbols are automatically added, representing semantic categories implied by the IS-A statements, i.e. human females and human males. The first new category (human females) can be thought of as the intersection of human and feminlneObJect or as the union of girl and woman 2, and similarly for human males. The signature resulting from the IS-A statements is shown in Figure 1 .",
"cite_spans": [
{
"start": 249,
"end": 262,
"text": "(Maier, 1980)",
"ref_id": "BIBREF9"
}
],
"ref_spans": [
{
"start": 946,
"end": 954,
"text": "Figure 1",
"ref_id": null
}
],
"eq_spans": [],
"section": "THE IS-A RELATION AMONG FEATURE VALUES",
"sec_num": null
},
{
"text": "Much work in computational linguistics is focussed around the application of unification to an informational structure that maps attribute names (also called feature names, slot names, or labels) to values (Kay, 1984a; Kay, 1984b; Shieber, 1985; Shieber, et al, 1986) . A value is either atomic or (recursively) another such mapping. These mappings are called by various names: feature structures, functional structures, f-structures, and feature matrices. The feature structures of PATR-II are most easily understood by viewing them as directed, acyclic graphs (DAGs) whose arcs are annotated with feature labels and whose leaves are annotated with atomic feature values (Shieber, 1985) .",
"cite_spans": [
{
"start": 206,
"end": 218,
"text": "(Kay, 1984a;",
"ref_id": null
},
{
"start": 219,
"end": 230,
"text": "Kay, 1984b;",
"ref_id": null
},
{
"start": 231,
"end": 245,
"text": "Shieber, 1985;",
"ref_id": "BIBREF16"
},
{
"start": 246,
"end": 267,
"text": "Shieber, et al, 1986)",
"ref_id": "BIBREF17"
},
{
"start": 672,
"end": 687,
"text": "(Shieber, 1985)",
"ref_id": "BIBREF16"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "IS-A statements are taken to be unrelated.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "2 Or anything in between. One is the most liberal interpretation, the other the most conservative. The signsture could be extended by adding both classes, and any number in between.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "IGs use C-terms, an informational structure that is best described as a rooted, possibly cyclic, directed graph. Each node (both leaf and interior) is annotated with a symbol from the signature. Each arc of the graph is labelled with a feature label (an attribute). The set of feature labels is unordered and is distinct from the signature. The formal definition of C-terms, given in set theoretic terms, is complicated in several ways beyond the scope of this presentation-see the definition of well-formed types in (Ait-Kaci, 1984) . We give several examples to give the flavor of C-terms.",
"cite_spans": [
{
"start": 517,
"end": 533,
"text": "(Ait-Kaci, 1984)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "Feature structures are often represented using a bracketed matrix notation, in addition to the DAG notation. C-terms, on the other hand, are represented using a textual notation similar to that of first-order terms. The syntax of the textual representation is given by the following extended BNF grammar 3. In this C-term the head symbol is missing, as is the head symbol of the subterm. When a symbol is missing, the most general symbol of the signature (T) is implied.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "In traditional first-order terms, a variable serves two purposes. First, as a wild card, it serves as a place holder which will match any term. Second, as a tag, one variable can constrain several positions in the term to be filled by the same structure. In C-terms, the wild card function is filled by the maximal symbol of the signature (T) which will match any C-term during unification. Variables are used exclusively for the tagging function to indicate C-term eore/erence. By convention, variables always begin with an uppercase letter while symbols and labels begin with lowercase letters and digits.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "In the following ~b-term, representing The man want8 to dance with Mary, X is a variable used to identify the subject of wants with the subject of dance.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "sentence ( subject ~ X: man, predicate ~ wants, verbComp ~ clause ( subject ~ X, predicate ~ dance, object ~ mary ))",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "If a variable X appears in a term tagging a subterm t, then all subterms tagged by other occurrences of X must be consistent with (i.e. unify with) t 4. If a variable appears without a subterm following it, the term consisting of simply the top symbol (T) is assumed. The constraint implied by variable coreference is not just equality of structure but equality of reference. Further unifications that add information to one sub-structure will necessarily add it to the other. Thus, in this example, X constrains the terms appearing at the paths subject=> and verbComp~subject~",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "to be the same term.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "In the ~b-term representation of the sentence The man with the toupee sneezed, shown below, the np filling the subject role, X, has two attributes. One is a qualifier filled by a relativeClause whose subject is X itself.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "sentence ( subject ~ X: np ( head ~ man, qualifier ~ relativeClause subject ~ X, predicate ~ wear, object ~ toupee)), predicate ~ sneezed)",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "As the graphical representation (in Figure 2 ) of this term clearly shows, this C-term is cyclic.",
"cite_spans": [],
"ref_spans": [
{
"start": 36,
"end": 44,
"text": "Figure 2",
"ref_id": null
}
],
"eq_spans": [],
"section": "C-TERMS AS FEATURE STRUCTURES",
"sec_num": null
},
{
"text": "The unification of two ~b-terms is similar to the unification of two feature structures in PATR-II or two first-order terms in logic. Unification of two terms t I and t 2 proceeds as follows. First, the head symbols of tl and t2\"are unified. That is, the GLB of the two symbols in the signature lattice becomes the head symbol of the result. Second, the subterms of t I and t, are unified. When t I and t 2 both contain the feature f, the corresponding subterms are unified and added as feature f of the result. If one term, say h, contains feature f and the other term does not, then the result will contain feature f with the value from h. This is the same result that would obtain if t2 contained feature f with value T. Finally, the subterm coreference constraints implied by the variables in t 1 and t 2 are respected. That is, the result is the least constrained ~b-term such that if two paths (addresses) in t 1 (or t2) are tagged by the same variable (i.e. they core/%r) then they will corefer in the result.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "UNIFICATION OF ~b-TERMS",
"sec_num": null
},
{
"text": "For example, when the C-term (agreement @ X: (number@singular), subject => (agreement@X))",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "UNIFICATION OF ~b-TERMS",
"sec_num": null
},
{
"text": "is unified with",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "UNIFICATION OF ~b-TERMS",
"sec_num": null
},
{
"text": "(subject@ (agreement@ (person@third)))",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "UNIFICATION OF ~b-TERMS",
"sec_num": null
},
{
"text": "the result is (agreement @ X: (number@singular, person@third) , subject @ (agreement@X))",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "UNIFICATION OF ~b-TERMS",
"sec_num": null
},
{
"text": "An IG consists of several IS-A statements and several grammar rul\u00a2~. A grammar rule is a definite clause which uses C-terms in place of the first-order literals used in first-order logic programming s. Much of the notation of Pro]og and DCGs is used. In particular, the :-symbol separates a rule head from the C-terms comprising the rule body. Analogously to Prolog, list-notation (using [, I, and ] ) can be used as a shorthand for C-terms representing lists and containing head and tail features. When the --> symbol is used instead of \"-, the rule is treated as a context-free grammar rule and the interpreter automatically appends two additional arguments (start and end) to facilitate parsing. The final syntactic sugar allows feature labels to be elided; sequentially numbered numeric labels are automatically supplied.",
"cite_spans": [
{
"start": 359,
"end": 399,
"text": "Prolog, list-notation (using [, I, and ]",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "Our first simple Inheritance Grammar consists of the rules:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "sent --> noun (Num) ,verb (Num) . noun (plural) --> [cats] . verb (plural) --> [meow] .",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "The sentence to be parsed is supplied as a goal 6 This is to be contrasted with LOGIN, in which \u00a2- Figure 2 . Graphical representation of a C-term.",
"cite_spans": [],
"ref_spans": [
{
"start": 99,
"end": 107,
"text": "Figure 2",
"ref_id": null
}
],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "clause, as in:",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": ":- sent ([cats,meow] , []) .",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "The interpreter first translates these clauses into the following equivalent IG clauses, expanding away the notational sugar, before execution begins. sent (start~Pl, end~P3) :noun (l~Num, start~Pl, end~P2)",
"cite_spans": [
{
"start": 156,
"end": 166,
"text": "(start~Pl,",
"ref_id": null
},
{
"start": 167,
"end": 174,
"text": "end~P3)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": ", verb (l~Num, start~P2, end~P3) . noun (l~plural, start~list (head, cats, tail~L) , end~L)",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": ". verb (l~plural, start~list (head,meow, tail~L) , end~L)",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": ".",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": ":- sent (start~list ( head,cats, tail~list ( head,meow, tail~nil)) , end~nil",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": ") .",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "As this example indicates, every DCG is an Inheritance Grammar. However, since the arguments may be arbitrary C-terms, IG can also accomodate feature structure manipulation.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "INHERITANCE GRAMMARS",
"sec_num": null
},
{
"text": "Several logic-based grammars have used semantic categorization of verb arguments to disambiguate word senses and fill case slots (e.g. Dahl, 1979; Dahl, 1981; McCord, 1980) . The primary motivation for using !b-terms for grammatical analysis is to facilitate such semantic type-class reasoning during the parsing stage.",
"cite_spans": [
{
"start": 135,
"end": 146,
"text": "Dahl, 1979;",
"ref_id": "BIBREF2"
},
{
"start": 147,
"end": 158,
"text": "Dahl, 1981;",
"ref_id": "BIBREF5"
},
{
"start": 159,
"end": 172,
"text": "McCord, 1980)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "TYPE-CLASS REASONING IN PARSING",
"sec_num": null
},
{
"text": "As an example, the DCG presented in (McCord, 1980) uses unification to do taxonomic reasoning. Two types unify iff one is a subtype of the other; the result is the most specific type. For example, if the first-order term smith:_ representing an untyped individual 6, is unified with the type expression X:person: student, representing the student subtype of person, the result is smith :person : student. terms replace first-order terms rather than predications.",
"cite_spans": [
{
"start": 36,
"end": 50,
"text": "(McCord, 1980)",
"ref_id": null
}
],
"ref_spans": [],
"eq_spans": [],
"section": "TYPE-CLASS REASONING IN PARSING",
"sec_num": null
},
{
"text": "e Here the colon is used as a right-associative infix operator meaning subtype.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "TYPE-CLASS REASONING IN PARSING",
"sec_num": null
},
{
"text": "While .this grammar achieves extensive coverage, we perceive two shortcomings to the approach. (1) The semantic hierarchy is somewhat inflexible because it is distributed throughout the lexicon, rather than being maintained separately. (2) Multiple Inheritance is not accommodated (although see McCord, 1985) . In IG, the \u00a2-term student can act as a typed variable and unifies with the C-term smith (yielding smith) assuming the presence of IS-A statements such as:",
"cite_spans": [
{
"start": 295,
"end": 308,
"text": "McCord, 1985)",
"ref_id": "BIBREF11"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "TYPE-CLASS REASONING IN PARSING",
"sec_num": null
},
{
"text": "student < person. {smith, Jones, brown} < student.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "TYPE-CLASS REASONING IN PARSING",
"sec_num": null
},
{
"text": "The taxonomy is specified separately-even with the potential of dynamic modification-and multiple inheritance is accommodated naturally.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "TYPE-CLASS REASONING IN PARSING",
"sec_num": null
},
{
"text": "The taxonomic reasoning mechanism of IG has applications in lexical and syntactic categorization as well as in semantic type-class reasoning. As an illustration which uses C-term predications, consider the problem of writing a grammar that accepts a prepositional phrase or a relative clause after a noun phrase but only accepts a prepositional phrase after the verb phrase. So The flower under the tree wilted, The flower that was under the tree wilted, and John ate under the tree should be accepted but not ",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "OTHER GRAMMATICAL APPLICATIONS OF TAXONOMIC REASONING",
"sec_num": null
},
{
"text": "We have implemented an IG development environment in Smalltalk on the Tektronix 4406. The IS-A statements are handled by an ordering package which dynamically performs the lattice extension and which allows interactive display of the ordering. Many of the techniques used in standard depth-first Prolog execution have been carried over to IG execution. To speed grammar execution, our system precompiles the grammar rules. To speed grammar development, incremental compilation allows individual rules to be compiled when modified. We are currently developing a large grammar using this environment.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "IMPLEMENTATION",
"sec_num": null
},
{
"text": "As in Prolog, top-down evaluation is not complete. Earley Deduction (Pereira and Warren, 1980; Porter, 1986) , a sound and complete evaluation strategy for Logic programs, frees the writer of DCGs from the worry of infinite left-recursion. Earley Deduction is essentially a generalized form of chart parsing (Kaplan, 1973; Winograd, 1983) , applicable to DCGs. We are investigating the application of alternative execution strategies, such as Earley Deduction and Extension Tables (Dietrich and Warren, 1986) to the execution of IGs.",
"cite_spans": [
{
"start": 68,
"end": 94,
"text": "(Pereira and Warren, 1980;",
"ref_id": "BIBREF12"
},
{
"start": 95,
"end": 108,
"text": "Porter, 1986)",
"ref_id": "BIBREF15"
},
{
"start": 308,
"end": 322,
"text": "(Kaplan, 1973;",
"ref_id": "BIBREF7"
},
{
"start": 323,
"end": 338,
"text": "Winograd, 1983)",
"ref_id": null
},
{
"start": 481,
"end": 508,
"text": "(Dietrich and Warren, 1986)",
"ref_id": "BIBREF6"
}
],
"ref_spans": [],
"eq_spans": [],
"section": "IMPLEMENTATION",
"sec_num": null
},
{
"text": "The vertical bar separates alternate constituents, brackets enclose optional constituents, and ellipses are used (loosely) to indicate repetition. The characters ( ) -> , and z are terminals.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
},
{
"text": "Normally, the subterm at X will be written following the first occurrence of X and all other occurrences of X will not include subterms.",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "",
"sec_num": null
}
],
"back_matter": [
{
"text": "Valuable interactions with the following people are gratefully acknowledged: Hassan A.it-Kaci, David Maier, David S. Warren, Fernando Pereira, and Lauri Karttunen. ",
"cite_spans": [],
"ref_spans": [],
"eq_spans": [],
"section": "ACKNOWLEDGEMENTS",
"sec_num": null
}
],
"bib_entries": {
"BIBREF0": {
"ref_id": "b0",
"title": "A Lattice Theoretic Approach to Computation Based on a Calculus of Partially Ordered Type Structures",
"authors": [
{
"first": "Hassan",
"middle": [],
"last": "Ajt-Kaci",
"suffix": ""
}
],
"year": 1984,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "AJt-Kaci, Hassan. 1984. A Lattice Theoretic Approach to Computation Based on a Calculus of Partially Ordered Type Structures, Ph.D. Dissertation, University of Pennsylvannia, Philadelphia, PA.",
"links": null
},
"BIBREF1": {
"ref_id": "b1",
"title": "LOGIN: A Logic Programming Language with Built-in Inheritance",
"authors": [
{
"first": "A",
"middle": [],
"last": "It~-Kaci",
"suffix": ""
},
{
"first": "Hassan",
"middle": [],
"last": "Nasr",
"suffix": ""
},
{
"first": "Roger",
"middle": [],
"last": "",
"suffix": ""
}
],
"year": 1986,
"venue": "Journal of Logic Program, ruing",
"volume": "3",
"issue": "3",
"pages": "185--216",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "A.it~-Kaci, Hassan and Nasr, Roger. 1986. LOGIN: A Logic Programming Language with Built-in Inheritance, Journal of Logic Program, ruing, 3(3):185-216.",
"links": null
},
"BIBREF2": {
"ref_id": "b2",
"title": "Logical Design of",
"authors": [
{
"first": "Veronica",
"middle": [],
"last": "Dahl",
"suffix": ""
}
],
"year": 1979,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Dahl, Veronica. 1979. Logical Design of",
"links": null
},
"BIBREF3": {
"ref_id": "b3",
"title": "Deductive NL Consultable Data Bases",
"authors": [],
"year": null,
"venue": "Proc",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Deductive NL Consultable Data Bases, Proc.",
"links": null
},
"BIBREF4": {
"ref_id": "b4",
"title": "on Very Large Data",
"authors": [
{
"first": "",
"middle": [],
"last": "Intl",
"suffix": ""
},
{
"first": "",
"middle": [],
"last": "Conf",
"suffix": ""
}
],
"year": null,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Intl. Conf. on Very Large Data Bascn, Rio de Janeiro.",
"links": null
},
"BIBREF5": {
"ref_id": "b5",
"title": "Translating Spanish into Logic through Logic",
"authors": [
{
"first": "Veronica",
"middle": [],
"last": "Dahl",
"suffix": ""
}
],
"year": 1981,
"venue": "Am. Journal of Comp. Linguistics",
"volume": "7",
"issue": "3",
"pages": "149--164",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Dahl, Veronica. 1981. Translating Span- ish into Logic through Logic, Am. Journal of Comp. Linguistics, 7(3):149-164.",
"links": null
},
"BIBREF6": {
"ref_id": "b6",
"title": "Extension Tables: Memo Relations in Logic Programming",
"authors": [
{
"first": "Susan",
"middle": [],
"last": "Dietrich",
"suffix": ""
},
{
"first": "",
"middle": [],
"last": "Wagner",
"suffix": ""
},
{
"first": "David",
"middle": [
"S"
],
"last": "Warren",
"suffix": ""
}
],
"year": 1986,
"venue": "C.S. Dept",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Dietrich, Susan Wagner and Warren, David S. 1986. Extension Tables: Memo Rela- tions in Logic Programming, Technical Report 86/18, C.S. Dept., SUNY, Stony Brook, New York.",
"links": null
},
"BIBREF7": {
"ref_id": "b7",
"title": "Functional Unification Grammar: A \"Formalism for Machine Translation",
"authors": [
{
"first": "Ronald",
"middle": [],
"last": "Kaplan",
"suffix": ""
}
],
"year": 1973,
"venue": "Proc. 2Znd Ann. Meeting of the Assoc. for Computational Linguistics (COLING)",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Kaplan, Ronald. 1973. A General Syn- tactic Processor, in: Randall Rustin, Ed., Natural Language ProcesMng, A_lgorithmics Press, New York, NY. Kay, Martin. 1984a. Functional Unification Grammar: A \"Formalism for Machine Translation, Proc. 2Znd Ann. Meeting of the Assoc. for Computational Linguistics (COLING), Stanford University, Palo Alto, CA. Kay, Martin. 1984b. Unification in",
"links": null
},
"BIBREF8": {
"ref_id": "b8",
"title": "Understanding and Logic Programming Conf",
"authors": [
{
"first": "Natural",
"middle": [],
"last": "Grammar",
"suffix": ""
},
{
"first": "",
"middle": [],
"last": "Lang",
"suffix": ""
}
],
"year": null,
"venue": "Proceedings, IRISA-INRIA",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Grammar, Natural Lang. Understanding and Logic Programming Conf. Proceedings, IRISA- INRIA, Rennes, France.",
"links": null
},
"BIBREF9": {
"ref_id": "b9",
"title": "DAGs as Lattices: Extended Abstract",
"authors": [
{
"first": "David",
"middle": [],
"last": "Maier",
"suffix": ""
}
],
"year": 1980,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Maier, David. 1980. DAGs as Lattices: Extended Abstract, Unpublished manuscript.",
"links": null
},
"BIBREF10": {
"ref_id": "b10",
"title": "Using Slots and Modifiers in Logic Grammars for Natural Language",
"authors": [
{
"first": "Michael",
"middle": [
"C"
],
"last": "Mecord",
"suffix": ""
}
],
"year": 1980,
"venue": "Artificial Intelligence",
"volume": "18",
"issue": "3",
"pages": "327--368",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "MeCord, Michael C. 1980. Using Slots and Modifiers in Logic Grammars for Natural Language, Artificial Intelligence, 18(3):327-368.",
"links": null
},
"BIBREF11": {
"ref_id": "b11",
"title": "Modular Logic Grammars",
"authors": [
{
"first": "Michael",
"middle": [
"C"
],
"last": "Mccord",
"suffix": ""
}
],
"year": 1985,
"venue": "Proc. of the eSrd ACL Conference",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "McCord, Michael C. 1985. Modular Logic Grammars, Proc. of the eSrd ACL Conference, Chicago, IL.",
"links": null
},
"BIBREF12": {
"ref_id": "b12",
"title": "Definite Clause Grammars for Language Analysis -A Survey of the Formalism and a Comparison with Augmented Transition Networks",
"authors": [
{
"first": "F",
"middle": [
"C N"
],
"last": "Pereira",
"suffix": ""
},
{
"first": "D",
"middle": [
"H D"
],
"last": "Warren",
"suffix": ""
}
],
"year": 1980,
"venue": "Artificial Intelligence",
"volume": "13",
"issue": "",
"pages": "231--278",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Pereira, F.C.N. and Warren, D.H.D. 1980. Definite Clause Grammars for Language Analysis -A Survey of the Formalism and a Comparison with Augmented Transition Net- works, Artificial Intelligence, 13:231-278.",
"links": null
},
"BIBREF14": {
"ref_id": "b14",
"title": "elst Annual Meeting of the Assoc. for Computational Linguistics",
"authors": [],
"year": null,
"venue": "",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Parsing as Deduction, elst Annual Meeting of the Assoc. for Computational Linguistics, Bos- ton, MA.",
"links": null
},
"BIBREF15": {
"ref_id": "b15",
"title": "Earley Deduction",
"authors": [
{
"first": "Harry",
"middle": [
"H"
],
"last": "Porter",
"suffix": ""
}
],
"year": 1986,
"venue": "Oregon Graduate Center",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Porter, Harry H. 1986. Earley Deduction, Technical Report CS/E-86-002, Oregon Gradu- ate Center, Beaverton, OR.",
"links": null
},
"BIBREF16": {
"ref_id": "b16",
"title": "An Introduction to Unification-Based Approaches to Grammar",
"authors": [
{
"first": "Stuart",
"middle": [
"M"
],
"last": "Shieber",
"suffix": ""
}
],
"year": 1985,
"venue": "Tutorial Session Notes, \u00a33rd Annual Meeting of the A~oc. for Computational Linguistics, Chicago",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Shieber, Stuart M. 1985. An Introduction to Unification-Based Approaches to Grammar, Tutorial Session Notes, \u00a33rd Annual Meeting of the A~oc. for Computational Linguistics, Chi- cago, IL.",
"links": null
},
"BIBREF17": {
"ref_id": "b17",
"title": "A Compilation of Papers on Unification-Based Grammar Formalisms, Parts I and II, Center for the Study of Language and Information",
"authors": [
{
"first": "S",
"middle": [
"M"
],
"last": "Shieber",
"suffix": ""
},
{
"first": "F",
"middle": [
"C N"
],
"last": "Pereira",
"suffix": ""
},
{
"first": "L",
"middle": [],
"last": "Karttunen",
"suffix": ""
},
{
"first": "M",
"middle": [],
"last": "Kay",
"suffix": ""
}
],
"year": 1983,
"venue": "Language aa a Cognitive Process",
"volume": "",
"issue": "",
"pages": "",
"other_ids": {},
"num": null,
"urls": [],
"raw_text": "Shieber, S.M., Pereira, F.C.N., Karttunen, L. and Kay, M. 1986. A Compilation of Papers on Unification-Based Grammar Formalisms, Parts I and II, Center for the Study of Language and Information, Stanford. Winograd, Terry. 1983. Language aa a Cognitive Process, Vol. Z: Syntax, Addison- Wesley, Reading, MA.",
"links": null
}
},
"ref_entries": {
"TABREF0": {
"text": "root node, np, is called the head symbol. This C-term contains two features, labelled by number and person.",
"type_str": "table",
"content": "<table><tr><td colspan=\"3\">np ( number ~ singular,</td><td/></tr><tr><td/><td colspan=\"2\">person ~ third)</td><td/></tr><tr><td/><td colspan=\"3\">The next example includes a subterm at</td></tr><tr><td colspan=\"2\">agreement:=>:</td><td/><td/></tr><tr><td>(cat</td><td colspan=\"2\">~ np,</td><td/></tr><tr><td colspan=\"2\">agreement ~</td><td colspan=\"2\">(number ~ singular,</td></tr><tr><td/><td/><td colspan=\"2\">person ~ third))</td></tr><tr><td/><td/><td/><td>term</td><td>::=</td><td>symbol [ featureList ]</td></tr><tr><td/><td/><td/><td/><td>[ featureList</td></tr><tr><td/><td/><td/><td colspan=\"2\">featureList ::=</td><td>( feature , feature ,</td></tr><tr><td/><td/><td/><td/><td>... , feature )</td></tr><tr><td/><td/><td/><td>feature</td><td>::=</td><td>label => term</td></tr><tr><td/><td/><td/><td/><td>[ label ~ variable [ : term ]</td></tr><tr><td/><td/><td/><td colspan=\"2\">Our first example contains the symbols</td></tr><tr><td/><td/><td/><td colspan=\"2\">np, singular,</td><td>and third.</td><td>The label of</td></tr><tr><td/><td colspan=\"2\">feminineObject</td><td>human</td><td>masculineObject</td></tr><tr><td/><td>adu i t</td><td>humanF ema i e</td><td colspan=\"2\">humanMa i e</td><td>chi i d</td></tr><tr><td/><td>woman</td><td>man</td><td>gir I</td><td>boy</td></tr><tr><td/><td/><td colspan=\"2\">Figure 1. A signature.</td></tr></table>",
"num": null,
"html": null
}
}
}
} |