What levels of linguistic rep resentation determine o r - PDF document

What levels of linguistic rep resentation determine o r constrain the semantic level? � W e b elieve that the f-structure is the p rima ry level that con- strains semantic interp retation. Of course, info rmation from other levels, such as c-structure, ma y also b e relevant. The relation b et w een the semantic structure and these other levels ma y b e enco ded directly b y a p rojection function, o r indirectly as a comp osition of p ro- jection functions b et w een other levels. � Even if other levels (e.g. c-structure) constrain scop e, w e needn't have a level of rep resentation at which info rmation from b oth levels is enco ded. W e can talk ab out the relation b et w een t w o levels in addition to relations within a level. 19 Do w e need a linguistic rep resentation of semantic info rmation? � Y es, fo r purp oses of talking ab out semantics. � Is the rep resentation \disp ensible"? P erhaps { dep ends on choice of semantic theo ry . Semantic structures can b e re- lated to a level of rep resentation of meaning (Discourse Rep- resentation Structures, Situation-Theo retic Infons, fo rmulas of intensional logic) o r directly to a mo del. 20

Building up a quanti�er: \Every p erson" 2 3 SPEC `every' 4 5 g : PRED `p erson' � " # V AR [ ] g : � RESTR [ ] every : 8 R ; P ; S: [ 8 Y : ( g V AR) ; Y � � ( g RESTR ) ; R ( Y )] � � � [ 8 X :g ; X � � S ; P ( X )] � � � S ; ev er y ( per son; P ) p erson : 8 X : ( g V AR) ; X � � ( g RESTR ) ; per son ( X ) � � every p erson : 8 P ; S: [ 8 X :g ; X � � S ; P ( X )] � � S ; ev er y ( per son; P ) � 17 What kind of info rmation needs to b e rep resented in a gramma r? � F-structure: rep resents syntactic a rgument structure � Semantic structure: rep resents semantic t yp e structure with no syntactic a rgument structure re�ex � Glue language: constrains ho w linguistic structures deter- mine the assembly of meanings (issues ab out relative scop e, scop e islands, t yp e raising, . . . ) { \grammatical semantics" � Meaning language: Meanings 18

\John w alks." f :[ ] � � 2 3 PRED `w alk < ( " SUBJ) > ' 4 5 � � f : SUBJ g : PRED `John' � g :[ ] � g ; j ohn � 8 X : ( f SUBJ ) ; X � � f ; w al k ( X ) � � f ; w al k ( j ohn ) � 15 Quanti�cation: \Every one w alks." f :[ ] � � 2 3 PRED `w alk < ( " SUBJ) > ' 6 7 h i f : 4 5 PRED `every one' SUBJ g : � g :[ ] � every one : 8 P ; S: [ 8 X :g ; X � � S ; P ( X )] � � S ; ev er y ( per son; P ) � w alks : 8 X : ( f SUBJ) ; X � � f ; w al k ( X ) � � every one w alks : f ; ev er y ( per son; w al k ) � 16

An a rchitecture fo r the syntax-semantics interface: Assemble meanings with instructions in a logical language � Use \glue language", linea r logic, to sp ecify ho w to put meanings together � Meaning language: y our choice; w e use higher-o rder inten- sional logic 13 \John" � � g : PRED `John' � g :[ ] ; j ohn � 14

Problems with va riable binding: 2 3 2 3 REL 8 2 3 6 7 6 7 6 7 [ ] V AR [ ] 6 7 6 7 6 7 6 7 h i " # 6 7 6 7 4 5 6 7 REL P 6 7 [ ] 6 7 4 5 RESTR 4 5 ARG [ ] 2 3 [ ] 6 7 2 3 6 7 REL 8 6 7 6 7 6 7 6 7 V AR [ ] 6 7 6 7 6 7 " # 6 7 6 7 6 7 REL P 6 7 6 7 4 5 RESTR 4 5 ARG [ ] 11 Problems with function application: 2 3 REL � 6 7 " # V AR [ ] 6 7 h i REL P 6 7 " # ARG [ ] ) 6 7 REL P ARG [ ] 6 7 4 5 RESTR ARG [ ] �X :P ( X ) ( Y ) ) P ( Y ) 12

Halvo rsen and Kaplan (1988), Projections and semantic description in LF G: � F o rm of meaning: attribute-value structure � Meaning determined b y p rojection from c-structure, indi- rectly related to f-structure � Meaning assembled b y accumulation of constraints on attribute- value pairs 9 Commonalities: � Sepa rate rep resentation of syntactic and semantic info rma- tion � F o rm of meaning: attribute-value structure; gives (mo re o r less) undersp eci�ed rep resentation of semantic info rmation � Meaning related directly to c-structure o r f-structure � Meaning assembly b y analysis of f-structure o r accumulation of constraints 10

F enstad et al. (1987), Situations, Language, and Logic: � F o rm of meaning: attribute-value structure, the sitschema, rep resenting a fo rmula in Situation Semantics � Meaning determined (in p rinciple) b y phonology , mo rphology , syntax, context � Meaning assembled b y accumulation of constraints on attribute- value pairs 7 Halvo rsen and Kaplan (1988), Projections and semantic description in LF G: S � � NP VP 2 3 " # � � PRED `w alk < ( " SUBJ) > ' PRED REL w alk 4 5 � � SUBJ PRED `John' ARG1 John N V John w alks 8

Halvo rsen (1983), Semantics fo r LF G: � F o rm of meaning rep resentation: attribute-value structure { F-structure and fo rmula of intensional logic a re disp ensible { Di�erent meaning language is p ossible � Meaning determined b y f-structure � Meaning assembled b y analysis of f-structure 5 F enstad et al. (1987), Situations, Language, and Logic: 2 3 2 3 PRED `w alk < ( " SUBJ) > ' 6 7 4 5 FSTRUCT � � 6 7 SUBJ PRED `John' 6 7 6 7 6 7 2 3 6 7 6 7 REL w al k 6 7 h i 6 7 6 7 6 7 6 7 IND j ohn ARG1 6 7 6 7 6 7 6 7 6 7 2 3 6 7 6 7 6 7 IND I N D : 1 6 7 6 7 SITSCHEMA 6 6 2 3 7 7 6 7 6 7 6 7 REL � 6 7 6 6 7 7 6 7 LOC 6 6 6 7 7 7 6 7 ARG.1 [ ] 6 COND 1 7 6 4 5 7 6 7 6 7 4 5 6 7 4 5 ARG.2 l 4 d 5 6

Halvo rsen (1983), Semantics fo r LF G: PRED-ARG con�guration 2 3 s v 1 1 4 . 5 If f is an f-structure of the fo rm . containing some v k . i s v n n that has an a rgument list, then (M PREDICA TE) = M s k i and fo r 0 < j � m, (M ARG j ) = M k l where m is the numb er of thematic a rguments of the semantic fo rm in s , and M is the semantic structure asso ciated with the i l f-structure designato r in the jth a rgument p osition. 3 \John w alks." 2 3 PRED `w alk < ( " SUBJ) > ' 4 5 � � f = k SUBJ PRED `John' 2 3 PREDICA TE w al k 2 3 6 7 6 7 CM �P :P ( j ohn ) 6 7 6 7 M = 6 7 k 6 7 ARG1 MODE CM 6 7 4 5 4 5 PM �P :P ( j ohn ) � F o rmula of intensional logic: w al k ( j ohn ) 4

Levels of semantic rep resentation in LF G Ma ry Dalrymple, John Lamping, and Vija y Sa rasw at Semantics W o rkshop at the LF G Collo quium and W o rkshops Grenoble, F rance August 26, 1996 1 � What is the fo rm of the meaning rep resentation? � What is the relation of the meaning rep resentation to other levels? � Ho w a re meanings put together? 2