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<?xml version="1.0" standalone="yes"?> <Paper uid="C94-2151"> <Title>NON-CONSTIT UENT CO()t:{.I)IN ATION: TIII!;OII.Y AND PRAC'I'ICI,;*</Title> <Section position="3" start_page="0" end_page="935" type="metho"> <SectionTitle> DELETION ACCOUNTS </SectionTitle> <Paragraph position="0"> In (,he last twenty to thirty yea.rs there have. been a sm'ies oP ae('ounts of coordina.tion involving various deletion me(:halfisms (FIYOHI (~.g. Gldtman, 1965 to vm~ ()i\]:sOUW, 1987). For exmnple, \['rom the following 'antee:edellt' se.\[ltellCe.~ 5) Sue gaw: l&quot;rcd a book by Chomsky and Sue gave</Paragraph> <Section position="1" start_page="0" end_page="935" type="sub_section"> <SectionTitle> Peter ~ paper I)y Chomsky </SectionTitle> <Paragraph position="0"> van Oirsouw ~dlows deletion of words to the left and to t\]le right of the conjunction, g~8 ~,~gl)eter a i)apcr t)y Chomslcy resulting in the sentence: 6) Sue gave Fred ~ book aud Peter a. l)a.per by (Jhomsky null Most deletion ac(:otmts assume that, deletion is l)erfol> reed under idctitity of words, httt don't amdyse what it means for two words to I)e i(lentleal (an ex('cption is van Oirsouw who diseussc.s 1)honological, lnorphologic~d and referential identity). (Jonsider the following example oF deletion.</Paragraph> <Paragraph position="1"> I'l'hc cx;mll)h:s Mmvc only consider substritlgs containing lllOl'O thl.tll ()1/(~ WOI'(I. Coordhiaiahm ~3f the individual words (whi,:h is necessarily consi.ituenl: coordination) is ~dso possible. Nat, ural exmlll)les involving lhe dei;erlnlncr, some, are di\[llcult to ~u:hlcw!, howew!r deiern'~htcr coordhla.tion is possible (cc)llsider: \] (t{d~l'~ /~t0tu ~u\]zclh,?r to ea:\])cc~ Jt:tu o~&quot; ~na~zl/ peopl{ to co~Nc).</Paragraph> <Paragraph position="2"> 7) John will drive and Mary built the drive * \[John will\] and \[Mary built the\] drive Here the two cases of drive are phonologically identical, but have different syntactic categories. Now consider: null 8) a * John bored \[the new hole\] and \[his f>llow workers\] null 1) * Mary came in \[a hurry\] and \[a taxi\] These are cases of 'zeugma' and are unacceptable except as jokes. It therelbre seems that the deleted words must have the same major syntactic category, and the same lexical meamng.</Paragraph> <Paragraph position="3"> lIowever, even if we fix both syntactic (:ategory and lexieal meaning, we still get some weird coordinations. For example, consider: 9) a * Sue sawi the manj \[through the telescope\]/ and \[with the troublesome kid\]j b *1 saw \[a friend of\] and \[the manuthcturer oil Mary's handbag In example (3) the two prepositions are attached differently, one to the verb saw, the other to the noun, man. In exmnple (b), attributed to Paul I)ekker, the two coRjunets require Mary's handbag to have a dif ferent syntactic structure: the bracketing appropriate \['or the first coajunct is \[\[a friend of Marv/' s handbag\]. The unacceptability of these examples suggests that word by word identity is insufficient, and that deleted material must have identicM syntactic structure, as well as identical lexieal meanings.</Paragraph> <Paragraph position="4"> Some of the most compelling arguments against deletion have been semantic. For examqfle, Lakoff and Peters (1969) argued that deletion accounts are inap propriate tbr certain constituent coordinations such gtS : 10) John and Mary are alike since the 'antecedent' sentence John are alike and Mary arc alike is nonsensical (it is also ungrannnatieal if we consider number agreement).</Paragraph> <Paragraph position="5"> However, semantically inappropriate or nonsensicM 'antecedents' are also possible when we consider non-constituent coordination. For example, consider 'antecedents' for the lbllowing: \] 1) *t \[The man who buys\] and \[the woman who sells\] rattlesnakes met outside b Many former \[soldiers living in England\] and \[resistance members living in N:an(:e\] have. similar memories c John sold dill>rent dealers \[a vase using his intensive sales technique\] and \[a bookcase using his market-stM/ technique\] (llb) is non-constituent coordination under the primary reading where the scope offouner does not contain living in England i.e. where the semantic bracke- null ting is: 12) \[\[former soldiers\] living in England\] Examples (a) and (b) could be expanded out at the NP level, but not at the S level, l\]owever (e) cannot be expanded out at any constituent level, whitsL retaining an a.ppropriate semantics. For exan~ple, expansion at the V1 ) level gives: 13) John sold different dealers a vase using his intensive sales technique and different dealers a bookease using his market-staJ1 technique '\['lms, although I,akoff and Peters' argmnenls count against standard deletion analyses, they do not coullt as general arguments against a unified treatment of constituent a,nd non-constituent coordination.</Paragraph> </Section> </Section> <Section position="4" start_page="935" end_page="935" type="metho"> <SectionTitle> SHARED STR.UCTURE </SectionTitle> <Paragraph position="0"> Consider the sentence: 14) John gave Mary a book m\]d Peter a. paper by Chomsky Instead of thinking of John 9ave and b.!\] Uhomsky as deleted, we can also think of them as shared 1)y the two conjuncts. This strncture can be represented as follows: Mary a bo{}k John gave a~M l)y Chomsky Pet, m&quot; a paper From the result of the previous section, cac.h (-onjm~ct must share not just the phonological materiM, but Mso the syntactic structure and the lexieal meanings. There are three main methods by which this sharing of structure can be achieved: phrasal coordination, 3-D coordination, and processing stra.tegies.</Paragraph> </Section> <Section position="5" start_page="935" end_page="936" type="metho"> <SectionTitle> PHRASAL COORDINATION </SectionTitle> <Paragraph position="0"> At first sight, analysing nou-constitnent coordination using phra.sal (i.e. constituent) coordilmtion seerns nonsensical. This is not the case. (2)or(linations are classified as non-constituent coordination if' the conjuncts fail to be constituents in a 'sta.n&~rd' phrase structure grammar. However, they may well be constituents in other grammm:s. For ex~ml)le, it has \])een argued that the weaker notiol, of constituency i)rovided by (Jategorial (\]rammars is {'xa(:tly what is required Bo allow all con.imml;s to be treated as constituents (Steedmal\] 1985).</Paragraph> <Paragraph position="1"> Phrasal coordination is exernplitied by the schema</Paragraph> <Paragraph position="3"> 2'\['here \]lave \])CCll vgLriolls argtlIllell(;S (st;elnllling \]'1&quot;13111 Hoss 1967) for the adopl;ion of a wtri~m~ of Ihls s,:heln~L, in which the coordinaling conjunctions is assoclatcd sMely with tJle lasl conjulR:t. 'Phe schema is revised as l;-)l\]ows:</Paragraph> <Paragraph position="5"> The sh;~red ma.t('+rial is necessaa:ily l,reated ident, ically \['or 0a,(:h COil>lille|; sine0 t;here is only a single COl)y: L\]le conjunct;ion is euibeddcd in a. siligle synt, ax Lrce.</Paragraph> <Paragraph position="6"> The phrasa. |coordhm, l, iou scheuia, requires each con-.</Paragraph> <Paragraph position="7"> junct, t,O be given a single l;yl)c, and for the ColijUlicl;.s and the +;olijllilc(,ion i/,s ;-i whole to I)c of ,;tic st'i, ilie I,yi)e. Prol)letns with the la.tl;er r(;(ltth:enicnt, WCi'c i)ointe(l OUl; I)5' Sa,g (',t M. (1985), who gawe l, he following (:cmiit;('re xlm~ pies: 15) a We wMked slowly and with great care I> I)a,L is ;~ II.cpul)lica.n and l)iX)ud of it, c I am }l(>l)ing~ Lo gel; all hiviLi~tion all(\[ oI)i,iulisti(: abOtll, lily Cl>a, llces Sag ei ;d. dca, I wil, h these e, xau\]ples by t,t'ei~t, ing care-+ gories as feala\]re Imndl0s, and allowing i:oordina,(,iou in (:as(;s where ,:her0 ~lrO t'Cil.(,tlrO~ in COtlllYlO\[l, I?o1: oxample, the l;WO colljtlllcl, s hi lisa,) .<;ha.re I,he f'ei~ture I-MANN\[&quot;J~ 3. As it, sta, nds, Lho ;_l.('(;()tlili, dot~s IIOg &'al with ex~t\[ill)les Sltch as the \['ollowing, 16) TNT deliver cf\[ic\]eid, ly aud on ,qliti(\[ay.'-; I\[er(; t.he a.(lverbia.\] I>lu!a,se wou\[(I l)re.suuud~ly I)e +MANN#ell and I, hc l>rel>OSi(,ional i)hras(~, t-'/'\]';M/'.</Paragraph> <Paragraph position="8"> I;ill'l,ll(~r eXa,liil)l(~,s which a,r(', prol>leula,(,ic fo\]' Sag (!1. a,l. aPS(': given I>y ,Iorg(~l\]SOll a.iid AI)cilld> (i!)92).</Paragraph> <Paragraph position="9"> All aAL(;l:ila, f, ivc, siiggeM, ed I>y Morrill (\]990) ;_,ii(l ~ilni\[ar Lo .Ioi'~c~l.son at>(I A l>cil|(i (\]!){)2)> is tx) ,is(': t,ho followhtg <:ooMinaLion ,'-.cholna:</Paragraph> <Paragraph position="11"> 'l'hi.s ,:loes not hupos(! auy (:onditiou i.iia(, i.h(; i,wo (:aix: <e)Ji;ics \]Yl~ au(I Y ,sharo alLyl,hing iu COliliilOli. I lowev(~l:> ,,he now ca.{.cgory .XVY is il,<,e(l tx) (!liStlr(~ Lhal. boi.h cui;(;gories ilr(! approl)ria.(x; in ,;he C('lltl,(~Xl;. For oxaiil-I>le, (15b) is a c(:(3)t;d>\[e since the co(>rdhla, gion Ioyl)e is NI'VAP, a.ud i.s sul)cat, egoriscs lbr Iml;li Nl's a.lld it Ps.</Paragraph> <Paragraph position="12"> A i;i/(;llCl* tnorc (li\[ficitlt l)rob\[oln is l;liat, (>f pix)vidh~g t;yi>es for all l)ossiblo (:olLjuncLs. C, onsi(ler tll(; lbllo+ wing: 17) it Sue ga.ve Fred a bool<: and Pel;er a I)itpcr I~ Mmy a(htdrcs aud ,%c thhA,:~ ~hl~ likes Pctx.' (~l) i:+ ,. <:(,,tJ,i,,<:t+i<,,, or t,,,,(, >i~-~ or ~>,,,, ~,l,,:~,~(,~. (i>) i~ a, (:ase of ~ili\]l)otil,(l(x\[ I/ight,-No(.le Raishtg' whcro l, he llOllll i)hrasc \])~l(r is onibc(ld(',(I ai, (lill'er(,,nt (l(;i'>iJis ill I, he I,wo (:oujiuicLs.</Paragraph> <Paragraph position="13"> There ha.vo I>ceii I.vvo iuai\]i iq>proa(;hes l;o (lea, thlg wii, h exalll\])les Stlch as (a,) liSillg pht'+~sal (:oor(ti11~'d;iOll. '\['he lirsL is 1,o hlLro(hlce ;'l.,l explicit l)l'()(ltlc:l; op(;ra, t, or (e.g. Wood 1!)88), allowing 1;y\])es ()\[' i~he l'ortrl NI'*NP+ The :-;econ(I is t.o use a cldculus hi whi(-h t;yl)eS c'~/ll iill(\[Cl'gO 'Lype-raishig' (c4.' ;. l)owi;y 1988), <, c<&quot;ui Im \['OlHll(~d \])y a,l>sl,l;a,('l;ioli (as ill t;h0 I,;tnll>ek ()aJ('tl\[llS, I,a.tul)cl<: 1958). The ell'e(q, is i,o l;l'eal. \[@(d (l book as a verb l)\]lr~se missi'llg ii, s verl>.</Paragraph> <Paragraph position="14"> :&quot;~al+g cL ;~.|. also suggest; ill, ii.ll,(~rnatlve li'(!~ltliiClll; ilSillg ;Lll ~Li)l\]arcn|ly <,l.hcrwlse unm,~tlw0.ed gr~tlnlll:Lr rule Ally\[ ~ - )- PI ~, The advantage of t~doi>ting ii genera\] al)sLractio\]l nteclmnism, its in the l,amlmk Ca.h'uhls, is thaL this a.lso provides a, l;l;(;ag\[/lelll, o\[e+xalnl)les such as (I)). Unfortuna,|;cly, the abilit, y Lo i)e, rfot:ln M~stracl.ion of caLe-I,;ories will, fmtcgio\]ml Lypes (which is required \['or (a)) a.lso allows shared m~d;eria.1 Lo get dift+erent, syuta.ct, ic aatalyses, restdt, iug in acccpta+nce of +dl the scntenrcs predict;ed by delel;ioIt account, s where identil;y of lcxical raLegories and lexicM senw, ntics is resl)ccl;e(l , bu(, not idetltity of syni,acti(: stru(:tur< l/,econsidcr: Is) *\] ..+~.w \[+,. r,:i(md or, +m(t lib(, ,.~umru+(-t.m'(;r or} Mary's handbag We can ol>tain identi(:al sy, lta(:l;ic tyl)es for a j:ric'nd q\]' and the man+@+ct.m+cr of by sulfl.racl;ing the lexi(:al types of I, saw, Mary, 's, and handbag from (he s(;ntcnl;e Lype S 4. Since (,he tyl>eS a.i:e idcu(,icM, (:oordination can Lhe.u I,ake pla(:e. Thus Lhe ability to '~qtll)I;ra(:(;' otto t;yl)e from anol;lte\]' allows I;he Lambek (',atcutus tXl replica+to a. delet, ion account, and it, therel)y suli'ers froru the sanlc 1)robt(>u,s.</Paragraph> <Paragraph position="15"> 'l'h(;re have 1)eet~ SOlllO l)rol>osa.ls t;o l'esLri(:L \[.he I,a,nbel,~ (Jah:uhls ill oi:der t.o pr(~v(mg such overg('.ue raLion, l:larry and Pi(:keriug (I 993) proposc it i:ah:ulus in whi(;h (17~+) is d(.alt with using a. produ(:L opera Lion, +rod absLra.ction is limited to (:atcgories which do l~ ()t ;~r(:l' ~; ~t functiou in tile dcriw, tiolL This a(;COUlll; nmlles reasot\]ably good crop,riced prcdi(:t;ions, t+hough it, does fa.il I'or t;1>(+' following exaniples: lit (a,l, (!at:h (:()ll, jllllCl, COlltariltS dil'l'Cl:CU(; iilIIllh(ws ()f rood,tiers o1' di\[l'er(;nt types (a,u adverb, all 1)hrase wil, h two i)reposiLiona\] 1)hrases). In (I)) the sul)l:a+tegorisa(:ion order is SWal)ped in the two (:on.bm(:t;s.</Paragraph> <Paragraph position="16"> Sttcces,.sful grea(,ill(;ilI, ()f llOli constil.uent (:oor(lim~t, ion using phrasal (:oor(lination se('ms I,o re(ILL,re ela.bor~d;e encs)(ling in (,h(; (;otljllll(;l; type of at siln\[->\[(? gen('.ralisat;iou: (:Otl.iltllCLq (:all (:oordina.te l)rovidcd Lhey a, re ac(:Cl~tM)h~ wi|;hin Lhe 8a.l.ite synt, act.ic conLext. ','he 3-1) al)l)roa(:hcs a.nd i)rocessing stra, t(:gies nse synt, acti(: (:ont.cxt more dircl:t;ly, and it is t;o these ,nel;hods whi(:\]l we llOW tllrll.</Paragraph> </Section> <Section position="6" start_page="936" end_page="937" type="metho"> <SectionTitle> 3-1) CoordinaLion </SectionTitle> <Paragraph position="0"> l+et; us briefly re.consider otu: cxplmlat.iou o1' ddct.ion.</Paragraph> <Paragraph position="1"> I&quot;,x+mqfle (6) was exl)lainc(l by saying t.hat t.he two sta'ings by Cho.msky and Sue galm are deleted iltldcr SOil,(+ IlOI,ioIt 0\[' ideutity. Ilowever, we could e(lmdly ',veil hame descrilled this as a process whereby the first; in,'-+La,nl:e of by Clwm.sk9 is ,nerged with the second (tlllder some noLion of idenLity), and the second insLance of ,9'uc 9av+! is merged wit,h the \[irst+ Merging word strings instead of deleting them does not help with the problems of deletion acconnts which we outlined earlier. In particular, it does not help to exclude examples (9a) and (gb) which suggest shared material must have identical syntactic structnre. However, once we have started to think in terms of merging, there is an obvious next step, which is to move f'rom inerging of word strings to rnerging of synt;ax trees. This is the move made by Goodall (1!)87), who advocates treating coordination as a. union of phrase markers: '% 'pasting together' one or, top of the other of two trees, with any identical nodes tnergil~g together&quot; ((;oo(hdl, 1987, p.20). We can visualise the result in terms o\[' a three-dimensional tree structure, where the merged material is on one plane, and the syntax trees for each eonjmlct are on two other planes. For example, consider the a-l) tree for example</Paragraph> <Paragraph position="3"> The merged part of' the tree inch,des all the nodes which dominate the shared matel:ial Sue gave. The coujmlets retain separate pla.nes (denoted here \] U using dot, ted and dashed lines respectively).</Paragraph> <Paragraph position="4"> (k)odall's aeco,mt does not deal with examples such as (171)), which he argues to I)e examples of'a different phenomcaon, llowew;r flmse can be incorporated into a ad) aeco,nt (e.g. Moltmamh 1992).</Paragraph> <Paragraph position="5"> There are various technical difliculties with Geedali's account (see e.g. van Oirsouw, 1987, and Moltnmnn, 11992). There is also a f'undanmnl,al l)lroblem COl,cerning semantic interpretation of coordinated structures (see Moltmanu, 1992 which provides a revised a.nd more complex 3-1) account based on Muadz, 1991).</Paragraph> <Paragraph position="6"> \[&quot;ot: coordinatioll el' unlike categories, as in the examples in (15), Goodatl proposes a treatment some what similar to Sag el; al. (1985). I\[owe.w~r there is still a problem in dealing with examples where there are clit\[>rent nurnbers of modifiers, such as (19a) or the lbllowing: 20) a. We can meet at the office or in London outside the theaure b 'FNT deliver efficiently and after 5pro in Edinburgh null (~onsider example (b). The synl;ac\[~ic structure appropriate for &quot;FNT' deliver eJficicnthd has one S node and two VP nodes, llowever, the structure fbr 7'N7' dellvet after 5pro in l','dinbm~h requires one S node and three VP nodes (or three S nodes and one VP node).</Paragraph> <Paragraph position="7"> The two structures therefore fail to merge since the structure dominating the shared material 7'N7' deliver must be identical. The nse of ordered phrase structure trees also excludes examples such as (19b).</Paragraph> <Paragraph position="8"> \]n summary, the /I-l) approaches correctly enforce identity of synta.ctic structure for shared material.</Paragraph> <Paragraph position="9"> ltowever, the way of characterising syntactic structure using (parts of) st, andard phrase structure trees results in a.n overly strict requirement of parallelism between the conjnncts. We will now consider processiug strategies, where syntactic structure of shared material is eharacterised more indirectly by the state of the parser.</Paragraph> </Section> <Section position="7" start_page="937" end_page="938" type="metho"> <SectionTitle> PROCESSING STRATEGIES </SectionTitle> <Paragraph position="0"> There have been several attempts to trea.t coordination by adapting pre-existing parsing strategies.</Paragraph> <Paragraph position="1"> For example, NFNs were adapted by Woods (1973), I)CGs by Dahl and MeCord (198:1), and chm:t parsers by lfaugeneder (\[992). Woods and Dahl & McCord's system are similar, ltaugeneder's system has very limited coverage.</Paragraph> <Paragraph position="2"> In Wood's SYSCONJ system, the pa.rscr can back ap to various points in the history of the parse, and parse the second conjunct according to the configura.lion fouud. I&quot;or example, in parsing, 21) John gave some books to l)eter and some papers I;o George at the point after encountering and, the parser can reaecess the configuration after parsing John gave i.e. a stack consisting of a sentence and a. verb phrase, and an arc traversal by the verb. The second eoldnnct is then parsed according to this contlguration.</Paragraph> <Paragraph position="3"> SYSCON./ does not imlnediately merge the two stack configurations after completing the second con.iunct, bnt, ins,ca.d, separa.tely parses both conjuncts in para.lM until a constituent is completed. For example, on parsing the sentence, 22) John gave Mary a book and Peter a paper about subj acen cy tim SYSCONJ systean sepa.rateIy parses Peter a paper about subjaceney and Mar9 a book about s.abjacencg before conjoining at the level of some enclosing constituent (for example \[.he verb phase). The result is theretbre similar to starting with the sentence: 23) .Jolm gave Mary a I)ook about, subjaeency and gave Peter a paper about subjacency As noted by Dahl and McCord, this meehanisrn means that SYSCONJ inherits the problems of nonsensical semantics which plague the deletion accounts, since John and Mart arc alike is treated the same as ,Jo/u~ a~v alike a~d Mart arc alike. The mechanism adso causes problen,s \[br dealing with nested coordination. Consider the sentence: 2d) John wanted to study medicine when he was elc-. ven, law when he was twc'lve, and to study nothing at all when he was eighteen The smallest constituenL containing to siudg medicine when he was eleven is the verb phase wanted to study medicine 'wh~m hc 'It;as clcve:n. \]lowevcr, if coordination of the first two conjunets occurs at tl~is level, it; is diflicull, to see how to deal with the final coidunet. Both Woods and l)ahl ,% McOord usc stack based configurations rather than ~ lifll parsing history. '\]'hus once something is popped off the stack its internal structure cannot bc accessed by the coordination rot,tint. This rules ont exmnplcs such as the following, 25) John gaw'~ some books to Mary and papers to Gcorgjc null where the NP, some books is COlnpleted prior to the conjunction being reached.</Paragraph> <Paragraph position="4"> Although I)rocessing a(;cOltlltS call provide reason al)le coverage of the coordination data, the exact predictions often require detaile.d examination of the code. This suggests a need for the more absl, ract level of description which dynamic grammars I)rovidc.</Paragraph> </Section> <Section position="8" start_page="938" end_page="940" type="metho"> <SectionTitle> DYNAMIC GRAMMARS </SectionTitle> <Paragraph position="0"> I)ynamics is ,lust the study of states and transiLions between sta~es. It can be used to specify the states of a left; to right parser and the possible mappings 10etween states, l&quot;or example, Milward (:1992b) provides a dynamic description o\[' a shift reduce l)arscr, and a dynamic description of a fully incremental parser I)asod on dependency grammar. Suitable languages for dynamics arc both forma.l and declarative., and are therefore also appropriate to exl)ress linguistic gcneralisations. null liu a l)yumnic Grammar (Milward 199210), each wood is regarded as an aetion whi(:h I)erforms some change in tim syntactic and semantic context, For cxaml)lc, a parse of the seutcnce John likes Mary betomes a mapping between an initial state, ci, through some intermediate states, c,, el, to a final state c/ i.e.</Paragraph> <Paragraph position="2"> duce parser, states encode the current stack configuration, and are related by rules which corrcsl)ond to shilTting and reducing a Since there are arl)itl:arily large, numbers of different stack configurations (the stack can I:)e of a.rbitrary size), the dynamics for shift reduce l)arsing involves the use of all infinite l/Ulrlher o\[ states. It thus differs from, say ATNs (Woods SShlft corresl)onds to: L ~-,' <X> *L on input of a word, W, where L is a wtrlablc stmMing for a list of cat;thin'its, ',*' is list COllC~tl:enation, mid X is the category for W. l~(!duce co,'rcsl)onds to <(;n ... Cl 2> ol, ~ <:('0 :> el, on (unpty inl)ul;, where C0 -} Cl ... On is a phrase sl.l'u(:lAire rule of I, he gramm~w. 1973), which have a tinite nmnber of states, augmented by an explicit recursion mechanism.</Paragraph> <Paragraph position="3"> Dynamic grammars can t)e presented as rewrite grammars by using transition types instead o\[' the more usual S or NP. For example, to get the parse above we need the lexieal entries: (~ John:ciF-~ca likes:caP+% MaJ:y:cbr-Ocf aud a single combination rule. schema which states that,</Paragraph> <Paragraph position="5"> A string of words is a sentence if it has the tyl)e , ci ~-->cf where ci and c/ are al)propriate initial and final states for a parse r.</Paragraph> <Paragraph position="6"> \[n a dynalnic grammar, any substring of a sentence <;all be assigned a type. \['%r example, likes and Ma W can 10e combined to get the type ('aF~rcf. Thus we have an appropriate hwel to perform substring cool dination. Dynamic grammars may be extended using the following combination rule (arm and or are both given the. special transition type CONe): l&quot;or any (;1, C2, C'1~}C2 --~ CIF+C2 CONJ C1~-~C2 Similar to SYSCON,1, this allows coordination when two conjmlcts map between the salue pairs of states. l'roecssing is also similar, with the eneountering of a conjtmetion causing back-up to an earlier stage in the parsing history. Howew~,r, since there is no popping of a stack, the fnll parsing history is awdlable s. I&quot;or example, lieu gave some books to ,flue has the transitions: null IJe,z fla~e sonle books to ,guc Ci --} (;k'-- Cl --O Cnt ---} C n -~&quot; e o --} (;/&quot; WC can then parse papers to Joc nsing the transitions: pal~rs to Joe C m (;~q ---)- e o ~-)- Cf Since the final state c/ matches the stab; immediately 1)efbre the conj/inction, the two strings caa combine. 'Fhe resnlting transit, ion diagram is as \['ollows: c i -o e h c/ _s books to ,%c and pollers to .loc ('m --~ C.f Sl,'or exmnple, for tile shift reduce parser, Ihe word .foh*t would gel the \[.ype, L ~+ <rip;> o\],, corresponding t. a shifting of tile NP onto the stack. The mnl)ty siring gets the I, yl)e, <Cn ... (;t > ol, F+ -<O0 > ol, where Co -+ (;1 .., (7,, is a rule of tile grammar, ,:orrespondlng to reduction.</Paragraph> <Paragraph position="7"> 7For the shift reduce parser, the initiM st~tc is tile ('Alll)ty list, <>, the final state is <s>.</Paragraph> <Paragraph position="8"> aSomethlng parallel to pOl)l)ing occm's tufty after tt c~)ordination. \[Iowever this is exactly what is required since we do not want (~verlappingcoordinal;i(m as in The gill ~md the or th~ bO~.l and the adult came.</Paragraph> <Paragraph position="9"> Iterated coordination (e.g. for examples such as Mary, .Petc~&quot; and Sue) can be treated ill tilt same way as iterated constituent coordination is treated in phrase strncture grammars. For example, each transitio~ type can be augmented with a feature (+/-) denoting whether or not; that transition has been iterated. The eoordination rule becomes: For miy C1, C2, (-JD+-C2 _,v Clio 1~/-(32 OONJ (Jt~-C2 Iterated types are formed as follows: \]&quot;or any O1, (J2, C1~0+O2 -o CI ~-FF/- C'2 O1~-+-(72 The precise gl:amnlaticality predictions lnacle 1oy the dynamic approach depend npon the characterisation of the states, and hence depend oil the partieulal: l)arsing strategy which is specified by the (lynaniics, tlowever there are some general predictions which can be inade. Firstly, consider conjuncts which correspond one t;o one ill the categories of the eel responding words. Here the eonjmletS must provide the same transitions, and heuce lIlnst be able to coo> dinate (this is a reflection of tile fact that processing can back np to any point in the parsing history). This predicts that ally substring of a sentence can eoordiilal;e with itself, and heuce that any snbstring of a sentence can act as a eol/junet. I&quot;or eonvel/ience we will call this the substrmg h;l/pothesis. Tills hypothesis has l)een In:oadly adopted in the work of van Oirsouw 1987, Barry and l)ickering 1993, and l)y work on the 1,anlbek Calculus (e.g. Moortgat 1988).</Paragraph> <Paragraph position="10"> Apparent counterexamples are at fbllows: 213) a * The woman spoke to George aild nlan to Peter null b * ,John told \[Mary Bill\] and \[Fred Slle\] was coming (Barry and Pickering 1993) I Iowever it; is dillicult to exchlde these using syntaetie constraints, without also exclnding the 1note acceptable: null 27) a Every woman spoke to (.leorge and lnan spoke to Peter b ,Iohn told the niotllers that their daughters and the fathers that their sons were all at the party 9 More natural examples where conj/lncts are forlned by \[raglnents l'rorrl different COllStit, uent.s are the foliowing: null 28) a The police fonnd sonic \[cars inside\] and \[lorries outside\] the warehouse b Everyone who I \[admire most came\] and \[admire least stayed away\] c Mary showed litany \[h'iends the weird books\] and \[eolleagues tilt lnore respectable pal)ors \] written by her mother The relative UlmCCel)tability of the examples in (26) is perhaps best explained as dne to violations of into9This exmnple is al.l.ributed by Barry and lqckerlng (1993) I.o Jmme Johmulessell.</Paragraph> <Paragraph position="11"> national requirements, rather than syntactic requirelnents (cf. Steedman, 1989), One case where the dynamic grammars correctly violate tile substring hypothesis is when a string already involves a coordination, lIere, the internal st;ates arc not aecessible, so we can't get interleaving of two coordinations, as in: 29) * The girl and tile or the boy and the adult came '\]'here may be an argument for similarly blocking co-ordination in cases which would involve the breaking apart of idioms or ot her structures which are nol; Stalldm:d eases of lexical Sld)categorisation. An example (due to Mark Steedman), which may be sneh a case, is the following, 30) * One lnan ill \[ten spoke against and twenty act ually protested\] As noted above, the precise granunaticalil;y predictions depend on the kind of parsing lnodel which is encoded in the states. In Milward (1992a), the dynarnics specifies a word-by-word incremental parser lbr a lexicalised version of dependency gramlnar. Fach state is a recursively defined category, similar to ~/cal;egory in Categorial Gramlnar. For exarnple, after parsing You can call me one possible state is a sentence missing a sentence lnoditier 1deg. This state is appropriate as the initial state R~r a parse of both dirccll?/, or of after ,Tpm thro,ugh my sccTvtary, resulting in a final state of category sentence. Thus examples Stlch as (19a) are dealt with, since the syntactic context after You can call me dots not distingnish between one or lnore than one subsequent modilier. This lack of distinction as to whethel: one or lnore modilier is expected is actually a necessary prereqnisite \['or performing decidable fl,lly word-by-word incremental interpretation (see Milward and Cooper, 1994, in these proceedings). Some of the problelns with eategorial granlmar accounts of coordination do reoccur with a dynamic acconnt based on the parser used ill Milward (1992a). For exaniple, 31) \[,/ohn\] and \[Mary thought that l'eter\] slept is predicted to 1oe a(x:eptable, as are the following, 32) a \['lbd~ w John\] and \[mary thonght that Peter\] slept I/ I he.ard \[that\] and \[that no-one else knew that\] Fred won the seholarship This second batch of examples is particularly dillicult to exclude withont malting changes to the eharacterisation of the states. A feature I>lus or lninns tensed vel% on each conjlmet does block them, but is difl-icnlt to motivate.</Paragraph> <Paragraph position="12"> I)ynanlie grammars can be regarded Imrely as forreal systems, as direct representations of proeessing, or as something inbetween (for example, ill the packed ldegl)ependency grammar does not have VP modifiers im.rallel parser described in Milward (1{)921)), the acl;ua.l pro'sing sl,~tes ~tro plwked w;i'SiOllS o\[' i;hc ,qt,al, es in /,he gr3.,llilliil, r). ;If + we consider I;he dyiiauiics t,o Im a direel, rol>reselil;~ti, ioll 0\[' in:ocessing, I,\[lell ;t dependence o1&quot; linguistic (lal;a upoii I)al',<dl~.g sl;~i;es woliid ou\[y Seelll /)bmsibl0 i\[' the parsing i)roces.<, corresl)olids, ~1; leasl; 1,0 S()l\[iO exl, ont,, wigli acl;iutl hunmn hulgnage IJrocos sing,, 'l'his brings it 1) Llle intriguing possilfility 1;ha, l, we c~_/,ll predict coordin;fl, ioli I)tcl;s l'roD;l kiiOWll 1)IX)('.(',SSillg (\[a,l;a,> a.nd vice versa,, bkn- ex3.niple, consider I;iie well kuown oxa.\[liDle Of gaxden i)ai, hing: 33) 'I'll(! horse ra.cecl lmSl, llhe ba.rii fell '\]'he ci~oic.e bctweeu l, ho Ilse o\[' facc(l as I,\[ie iiiaili verb, or ~l,s pi~rt o\[' i;ho i'edllCC(t relative is tb<-Jtla.lly IISSlllI'I(;(\[ I,(/ l)e within 1,he \]'lX'i, gliielll, 1,\]l,'? \]lol'.sfs v(Iccd, .quggestittg I;lii~l; I;here m'e I;wo disi,inguished parsing stai,cs ~flTter raced. 'l'hus this correcl, ly predicts l;he uiuux'el)l,alfility o\[&quot; I, he following: 3d) * The horse raced \[lmsi, 1,1,,:~ Imru \['ell\[ and \[heside \[,he hedge\]</Paragraph> </Section> class="xml-element"></Paper>