CHAPTER Y. DEVELOPMENT TRANSLATION ALGORITHM IIaIMPLEHENTATIOB As discussed ea.r 1 ier, 8. hllm8.n t r8.n l.a.tor l'ecogn ises various sentence parts on the basis of the typology of sentence-constituent form8.t ions, In other words" 8. translator matches a sentential component and/or combination thereof of the given sentence with the typologies of sentence parts for the purpose of their Similarly, identification of different syntactic structures is carried out by phrase structure analysis," Based on typology of sentence parts, dicussed in chapter III, it is possible to' formula.te multiple number of tree-structu.res. In fa.ct, various types of subjects, predicates, attributes, object and adverbial modifiers find reflection in the so- called NP a.nd VP/RVP structures (tra.ditiona.lly known as subject and predioateof the sentence respectively), and it becomes pra.ctics.ble to perform mechanica.l tra.ns lat ion of Russian sentences, including pretty long syntactic formations, that fit in NP and VP structures involving different types of subjects, predicates, etc. It is true that a.ll permutations and combinations of the prima.ries and secondary sentence parts may not be logically possible (due to predicativity condition), and this fa.ctor has been taken care of while developing the translation program. Given below a.re a. few examples of different parse 105
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CHAPTER Y.
DEVELOPMENT ~ TRANSLATION ALGORITHM ~ IIaIMPLEHENTATIOB
As discussed ea.r 1 ier, 8. hllm8.n t r8.n l.a.tor l'ecogn ises
various sentence parts on the basis of the typology of
sentence-constituent form8.t ions, In other words" 8.
translator matches a sentential component and/or combination
thereof of the given sentence with the typologies of
sentence parts for the purpose of their identification~
Similarly, identification of different syntactic structures
is carried out by phrase structure analysis," Based on
typology of sentence parts, dicussed in chapter III, it is
possible to' formula.te multiple number of tree-structu.res.
In fa.ct, various types of subjects, predicates, attributes,
object and adverbial modifiers find reflection in the so-
called NP a.nd VP/RVP structures (tra.ditiona.lly known as
subject and predioateof the sentence respectively), and it
becomes pra.ctics.ble to perform mechanica.l tra.ns lat ion of
Russian sentences, including pretty long syntactic
formations, that fit in NP and VP structures involving
different types of subjects, predicates, etc. It is true
that a.ll permutations and combinations of the prima.ries and
secondary sentence parts may not be logically possible (due
to predicativity condition), and this fa.ctor has been taken
care of while developing the translation program.
Given below a.re a. few examples of different parse
105
trees/phrase structure trees which explain natu.ral la.nguage
grammar (here Russian grammar) in the form of context-free
grammar/logic gramma.r, showing forma.l representation of
various sentence parts in the form of phrase structures and
the structure of Russian flentences. (In fa.ct > it is these
parse trees which are to be constructed automatically for
the Russain gra.rnma.r-our parsing problem that we sha.ll
discuss next).
FIG- 1
Gra.mmar:
LT: AT:
s ---) NP VP N NP --) Pro
NP·-:> Aclj N) Pro
NP --) APN (Oli- Adj VP --) VNP AdvP V AP --) Adj Adv AdVP-) Adv Conj Adv Adv
PH..C i
On Sub
he he
v . I 1 Chlt'3. Pred
Conj
A~ I ~ t\Jj< N , . ,
tekstovoi material Attr Obj
read textu8.1 res.d -h\,e textu'3.l
m.aterial material
106
---) It'lateri'3.1 ---) on ---) tekstovoi ---) chital ---) gromko ---) privil'no ---) i
loudly loudly
and correctly and correctly
FIG- 2
Gramms.r:
S ---) NP vp N ---) stlJ.denty NP---> N N ---) ks.nikuly NP---) APN Ad,j ---) zimnye vp---) AdvP V NP V ---) proveli AP---) Ad,j Adv ---) vese~o AdvP-> Adv
s
!\ 'r (N.\.'.,,: ... A1d.i "'\{
~,
zimnye kanikuly
N Adv . --
" ~ )
\ , d
studenty veselo proveli Sub AM Pred Attr Obj
LT: students Rlerri ly spent winter holidays AT: the studen-ts spent winter holidays merrily
107
Gr8.mmar!
S ---)
NP---> NP---> VP---> PP---)
PM I onQ.. Sub
LT: she AT: she
FIG-
NP VP Pro N Aux V PP PP Prep NP
s
~ ....... ~~ I_~-K ,~~/ >~~?
khochet igrat' Pred
wants to p18.y wants to play
108
3
N ---) parke Pro ---) ona Pro ---) n8.mi All X ---) khochet V ---) igra.t' Prep ---) s Prep ---> v
pp
-A . rp l~fj r
P'hOi. PA.O I"· N ,""t' I. .,' / I s nam1 i parke
I Obj AM with us in park with us in the park
Grammar:
LT: AT:
S -_._> NP VP HP---> Pro NP---> Proper N VP--'-> V NP VP vp---) V
.tUJ , "" ",. /./
oni poprosili Sub Pred
they 3.sked they asked
FIG- 4
Proper N ---) IVana. Pro ---) oni V ---) poprosili V ---> udalit'sY8.
PMP'~IN 'I I Ivs.ns. uda.l it' Sy3.
Obj I Obj Ivan to lea.ve Ivan to leave
1139
FIG- 5
Grallll8.r:
S ---) SP VP Proper N ---) Vladillir NP---> Pro Proper I ---> Volgograda NP---> Proper N Pro ---> nail vp---) V pp pp V ---) priekhal pp---> Prep IP Prep ---) k
Prep ---) iz
5
NP
~f\.OrVv N A r~~ NP
J
Vladillir priekhal k i iz nail
Sub Pred I Obj AM LT: Vladimir calle to us froll Volgograd AT: Vladil1ir c8.Ile to us froll Volgograd
110
Grammar:
LT: AT:
S ---) NP VP NP---> N NP---)'APN VP---> Aux V PP PP---) Prep NP AP---) Adj AP AP---) Adj
.. Af At\] ¥J
, t'" t e .1 1nos.rannye Attribute
these foreign these foreign
s
tutisty Sub
tourists tourists
FIG- 6
N ---) turisty N ---} marte Adj ---) e'ti Adj ---) inostra.nnye Aux' ---) khotyat V ---) puteshestvovat' Prep ---) v
pp
il /"". ~ _ J..4
. /1/ '.> ~,j "'J ~
kh6tya.t PI) teshestvovat 'v' marte Predicate AM
want to tra.vel in Ma.rch want to travel in March
111
FIG- 7
Gr~.mrn3.r :
S ---) NP VP N ---)
NP----- > N N ---)
NP---> APM N ---)
VP---> VNP pp Adj ---> pp---> Prep NP Adj ---)
AP---> Adj AP Adj ---)
AP---> Adj V ---)
Prep ---)
s
Ptlih Adj () ,I. J .:> .
e t1 ~nJodye lyudl Attr Suh
IT:these young peopJe accomplished this ~redt feet tor the sa~e of aotherland AT:these '{OUill} people accomplished this ~reat feet for the sakE- of ilotherlan..-l
112
lyudi podvig rodiny e'ti molodye e'tot sovershili r~.di
"
FIG- 8
Gra.lIlma.r:
S ---) NP VP Proper N ---)
NP---) Proper N Proper N ---)
NP---) N N ---> NP---) AP N Adj ---> VP---> AUK V pp pp Adj ---> pp---> Prep NP Aux ---)
AP---> Adj AP V ---)
AP---- > Adj Prep ---)
Prep --->
NP
LT: Russia contillueE. to )lrotest i1qainst this up.justiiied lel!islilticn ill UNO PoT: Russia continues to protest al!ainst this ur.justiiied le~islation in UNO
113 I .
Rossia.. OON' zakonodatel'stva e'togo nespra.vedl ivogo prodolzhaet vozra.ha.t' protiv v
S ---> NP llP NP---> ~Jt.cl;)Vt...."N NP---) Pro . VP---) NP V
s
.' NP
I P.Jt,o p-vv N
I . \>fU1 I
G8.l~na. tet>Y8. Sub Obj
Ga.lina you Galin3. loves
FIG- 15
PKol~N Pro V
" I
lyubit Pred
loves you
120
---) Gs.lins. ---) teby8. ---) lyubit
LT: AT:
FIG-16
Gr8.mlv,u:
S ---> NP VP Proper Nt ---> Ivan NP ---> NP 1 Conj NP2 Proper N2 ---) Sergei NP1---) Proper Nl N NP Z---) Proper NZ Adj NP ---) AP N A 1.1 X VP ---) AUx V NP V AP ---) Adj Conj
s
T' Co,nj
r~op,'Vt. NIt r]l..O ~ N2.
I . IV8.n Serge~
Subject Ivan and Sergei are Iva.n and Sergei are
pytayutsya res hit , Predic8.te
trying to solve the trying to solve the
--.--~--~
---) zadachi ---) trlldneishie ---) pytS.YlltSya ---) reshit' ---) i
-NP
~ AP ',N I .
A~' ,J
I trudneishie z8.d8.chi
Attr Obj most difficult problems most difficult problems
FIG- 17
Grammar:
S ---) NP VP Proper N ---) Igr NP ---) Proper N N ---) armiYll NP ---) N V ---) postllpil VP ---) V AdvP PP V ---> sluzhit' PP ---) Prep NP Prep ---) v AdvP ---) V
s
AdliP P l"t.-o p -e J"t, N J pp
/\ I fJn.ep t'l p
I ~ Igr postupil sluzhit' v 8.rmiyu
Sub Pred AM (of purpose) AM (of pls.ce) LT: Igor came to serve in S.rlTly AT: Igor came to serve· in the army
122
FIG- 18
Gr8.muu~.r ;
LT: AT;
S ---) 1'1P VP N ---) knigi NP ---) N AP N ---) stole NP ---) 1'1 Adj ---) Vlad imir8. VP ---) v PP Adj ---) pis , mennom PP ---) Prep NP V ---) lezh8.t AP ---) Adj Prep ---) ns.
(Note: Since Russi8.n does not follow the'criterion of inte:Tupta.bility', the word "Vladim.ir8." (genitive of Vladimir) with inflection suffix's. has been tak$n as a single lexical unit)
S'
N AP ~ pp
AL ~.~ ..
p.J1.e f S\. P
I ~~. , Arj ~ knigi Vl8.d imir8. lezh8,t na pis'mennom stole
Sub Attr Pred Attr AM books Vl8.d imir' s 8.re lying on writing t8.ble Vladimir's books are hring on the writing t8.ble
123
Grammar:
S ---)
NP ---}
NP ---)
NP ---)
VP ---)
PP ---)
AP ---)
nl8,l' ohik Sub
LT: boy AT:the boy
FIG- 19
NP VP N ---)
N PP N ---)
N N ---)
A~ Adj ---)
v PP v ---)
Prep NP Prep ---)
Adj
s
/\ p/(e.~ :Np
a ________
AP N \ ,
AdJ
I v mekhovoi
Attr (without in fur
shapke agreement)
in fur
124
ca.p ca.p
ma.l' ohik sha.pke sa.du mekhovoi gulyal v
gulya.l Pred
strolled strolled
v sadll AM
in parl in the par
Grammar:
LT: AT:
S ---) NP VP NP ---) N PP NP ---) N VP --'-) V NP PP ---) Prep NP AP ---) Ad.j
NP
~ N pp
otets Sub
f8.ther fa.tiler
/\ s
with 8.nd
NfP
sy-nom Sub
son son
s
FIG- 20
N ---)
N ---)
N ---)
Adj ---)
V ---)
Prep ---)
'-.1.
rs.zr8.b8.t YV8.1 i Pred.
worked out worked out
125
otets synom. plany budushchie razra.ba.tyval i s
Nfl ~~.
AP ~ A~j I
\ . budushch1e plany Attr Obj
future future
pl8.ns plans
· FIG- 21
Gra.mma.r:
S --_.) NP VP N ---) syn NP ---) AP N Adj ---) ego VP ---} AdvP V AdvP Adv ---) khorosho AP ---) Adj Adv ---> po-rl.lsskt AdvP ---:> Adv V ---) govorit
"'-iP
AP N AdvP ''-1 J I
Aot' AcJ.v Aqv J l J '/ govorit ego syn khorosho po-russki
Attr Sub AM Pred AM LT: his son well speaks Rl.lssis.n AT: his son spes,ks Russis.n well
126
FIG- 22
Gramma.r:
S ---) NP VP N ---) NP ---) APN N ---) VP ---) V NP PP N ---) PP ---) Prep NP Adj ---) AP ---) Adj AP Adj -_._)
AP ---) Adj Adj ---)
Adj ---)
V ---)
Prep ---)
s
Ap J0p y
I
LT;' :( '{ollng scientists got the highest iiworc for their nel'l invention In: the ,(ollng scienti!.',ts got the hiqhe~t award far their ne .. inventirHl
127
l.1chenye na.gra.dl.l otknytie e'ti molodye vySOC ha.ishIlYl.1 novoe po h.lf.~hi 1 i za.
Gr8.mm8.r:
LT: AT:
S NP AP AP
dOll
Sub house my
~, ",'"
---) NP copula AP N --..,> k!qm ---> NAP ---> Adj AP ---> Adj
---) NP Copula NP ---) Proper N ---) AP N ---) Adj
FIG- 24
Proper N N Adj Copula
---)
---)
---)
---)
Ivs.n 8.rtist ta18.nt 1 ivyi cp
(Note: Copula and the link verb are synonymous in our context). .
LT: Ivan AT: IV8.n
Gramm8.r:
S NP NP
S .
is 8.
---) NP VP ---) Pro ---) AP N
~ A.P ____
A10U N
talant~ivYi ~rtist Attr (of the Pred) Pred
talented ts.lented
FIG- 248.)
N Pro Adj
artist s.rt ist
---) komnate ---) nikto ---) e'toi
VP ---) p8.rticle V PP V ---) sps.l PP ---) Pred NP Prep ---) v AP ---) Adj Ps.rt ic le-) ne
s-
Vp
r nikto ne spal
.R·'P ----~.~ Pi1e1'- ~p \ ~p.,..... __ ~'
, t A-~J k)' t e .01. omn.a e v
LT: nobody not slept in this room AT: nobody slept in this room
129
FIG- 25
Gramm.ar:
S ---) NP VP N ---) studen tl3.m NP ---) Pro N ---> knigi NP ---) AP N N ---) tsentre VP ---) V MP NP PP Pro ---) oni PP ---) Prep NP Adj ---) na.shim AP ---) Adj Adj ---) interesnye
Adj ---) klll'turnonl V ..:.--) poda.rili Prep ---) "
s
. NP
v
Px-o NP
ni pods.rili ns.shim studentaln interesnye knigi "
A0~ I_I' I.
AOJ I .' I k'ul'tlJ.rnom tsentre
Sub Pred Attr I ObjAttr Obj Attr AM
LT:they preserited our studenta interesting books in Cultura.l centre AT:they presented our students interesting books in the Cultural centre
130 .
FIG- 26
Granrm.8.r:
LT: AT:
S ---) NP VP Numeral--) dve MP --~) Nu.meral AP N N ---) knigi MP ---) N N ---) stole VP ---) V PP Adj ---) malen'kie PP ---) Prep NP V ---) lezhat AP ---) Adj Prep ---) na
(Note: Here the term Numeral has been used both as ~ funct ional 18.be 1 8.nd 8.S a c 18.s5 l8.be 1 )
s
NP
pp N u Jrl, IP N
MJ P,:e..p ~p N
dve malen'kie knigi lezhs.t I na stole Numeral Attr Su.b Pred AM
two Slt18.11 books are lying on ta.ble two sma.ll books 8.re lying on the' t8.ble
131
Gra,mmar:
LT: AT:
S NP NP NP VP PP AP AP
NP
lilY Sub
---)
---)
---)
---)
---)
---)
---)
---)
s
NP VP Pro PP Proper AP N V NP Prep NP Adj AP Adj
~o!'e with Victor Vietor 3,nd I
N
FIG- 27
Proper N-> Viktorom N ---) slov8,r ,
Pro ---) my Adj ---> novyi V ---) matematicheskii Prep ---) c· .;>
NP
Ap
~ Ac!- Ap
U I I AdJ' t 'I' , t ~ t' h k" 1 ' SOS.8Vl 1 nOVY1 ma.ema.1C eS~ll s oval'
Pred Attr Obj compiled new mathematical dictionary compiled a new mathematical dictionary
132
FIG- 28
Grammar:
S ---) NP VP NP ---) Pro N NP ---) AP N VP ---) AUX V NP PP PP ---> Prep NP AP ---) Adj Aft AP ---) Ad,j
s
i'\p
r T
Ja khochu poseti{ interesnye Sub Predicate Attr
LT: I want to visit interesting AT: I want to visit interesting
N --:--) u)esta N ---) gorode Pro ---) 18. Adj ---) interesnye Adj ---) e'tom Adj ---) istotichskom Aux ---) khochu V ---) poset ie Prep ---) V
N
AP ~
A~~ I ~
't: . . h' k d mesta v e ~om 1stor1C es om goro .e Obj Attribute AM
places in this historical city places in this historical city
133
We have listed above a few illustrative examples of parse trees
Here the following points may be noted:
l)For the purpose of simplification we have not
reflected punctuation marks in the parse trees.
However. this could be done as follows: S-)'Y\ ~ ,
S/~ ~ C' s - 1Y\C\.J' -::r s ..r1'Y1o.i,.. pL1nG ,) ~. f il'\o.i-Pt.lll c . J
NP vp
Pr 'V~ Jt..O NP
I Oil1 ,.( ':tMt N .
\.M 1<'Y\o\~ H~ '~ JtRCAcli"j CI. booK
2) In Russian. numerals, in a way. are attributes~
howeve~ in the present work they (like determiners in
English) ha.ve been used both as a functiona.l la.bel
and 8.S a class label. in
determiners ("members of a. subc l8.ss of
English
English
adjectival words that limit the nouns they modify in
a special way and that usually are placed before
descriptive adjectives") include a variety of words.
for instance, pre-articles (several of. many of. both
of). articles (def and nondef-thej
demonstrative pronouns (this, these ... ),
sOll'le) • b numers "
(cardinal, ordinal one, two, three ...• first.
second .... ). In our present3.t ion, we ha.ve ta.ken
pr'onomia.l adj ect ives, demonstrat ive pronouns, ord inal
numbers in the ca.tegory of a.djectives as they 8.re
clearly marked as attributes (normally adjectives).
Here it lIl8:Y be added th8.t the term "determiner" ha.s
134
only "'3.rticles" (a term used for determiners in
tra.d it ion'3.l English grammar) as the later is
generally restricted to the definitive article (the)
and indefinite a.rticle (a).
3) In schemes (parse-trees) and in earlierexpla.nations
also we have indicated preposition a.s constituent
e lemen t of '3. sentence p'3.rt. subj ect) under the "hes.d"
word. For insts.nce:
On zhivet yMoskye.
AM
(He lives in Moscow).
Ons. priekhs.la ~'detmi.
I Obj
(She ca.me with children)
4) Earlier, we discussed the structure of a Russian
sentence in terms of sentence parts (cf. Subject with
Attribute + Predica.te + Object with Attribute +
Adverbia.l Modifier). However, after the realisation
of different sentence parts by
speech (npun. pronoun ..... ) the
Russian sentence may appear as:
vs.rious ps.rts
structure of
of
8.
Adjective + Noun + Verb + Adjective + Noun +
Preposition + Noun
135
sentences (small and large) could be represented in
terms of the parts of speech. In fact, the above
structure of a Russian sentence is a combination of
The grammar consists of a set of rules, here shown on
to a line. Each rule specifies a form that a certain kind
of phra.se can tS.ke. The first rule says that a sentence
consists of a phrase called a noun_phrase (a sentence can
take the form: a noun_phra.se.1followed by s. verb_phr8.se). The
second, third, fourth, fifth, sixth, a.nd seventh rules of
the grammar tell us what constitute grammatical forms of for
other phrases. The other rules in the grs.lUlUs.r SS.y how some
phr8.se can be ms.de up in terms of s.ctus.l words, rS.ther in
terms of slls.ller phrases. The things on the right hand side
nS.me 8.ctu8.1 words of. the 18.ngIl8.ge ( Russ i8.n ) , so that the
rule
numeral ---) dve.
c8.n be res.d S.S!
A numeral can take the form: the word dve. H8.ving
explained the gr8.mm.8.r, we can begin to see what sequences of
words are actually grammatical sentences according to it,
138
(sinoe this is a small grammar. it ~ill aocept sentenoes
formed out of fifteen different words). If we wish to
investigate whether a given sentence of words is aotually a
sentenoe s.ocordingly to these oriteria we, need to s.pply the
first rule to ask.
does the sequence deoompose into two phrase, such ths.t the first is 8.n 8.ccepts.ble noun_phrase and the second is a valid verb_phr~se?
Then in order to test whether the first phrase is a
noun_phrase, we need to s.pply the second rule 8.sking.
does it decompose into a numeral followed by s.n 8.djective a.nd then followed by a. noun?
and so on. At the end, if we.succeed~ ~e will have looked
at 8.11 the phrases a.nd sub-phrases of the sentence. 8.S
speoified by the grammar, and will have established a
structure like, for instanoe: (see fig. on next page)
This dia.grs.m (s. pa.rse tree for the sentence) shows
the phrase structure of the sentence.
We h~.ve seen how hs.ving a. grs.mms.r for Russia.n me~ms
th8.t we can construct pS.rse tree to show the structure of
Russian sentences. The prQblem of constructing a. pa.rse
tree for a. sentence, given 8. gra.mm.a.r, is called, as
m~ntioned earlier, the parsing problem. A computer program
that constructs parse trees for sentence of a language is
cs.lIed a. pa.rser.
Now let us see how a Russian sentence is parsed
aocording to the a.bove-mentioned grammar. Since 8. Prolog
progra.m (pa.rser), which pa.rse simple Russian sentences
139
( tWO
noUn:" phR..a.se
L\~J ~d:tve
p;l",en~orn
automatioallY. involves testing to see if something is a
sentenoe) let us define a predioate sentenoe. -~ x -" ... "----<; .. __ 0_- ..-.~... __ ;:,_-..,_.~" ''.~ ~.-",!-,_.yr ....... __ _
- -~/ .... This predicate will
succeed . if a sentence can be parsed properly. and fails if
it cannot. For example, if this predicate is applied to the
sentence: dve malen'kie knigi lezhatns. e'tom pis'mennom
stole should fail. since this sentence oannot be parsed
according to our grammar.
Now consider the problem of checking that a list of
words ( a sentence is held as a Prolog list) is a valid
sentence. A list of words is a valid sentence if:
1) the list has a valid noun phrase at the front;
2) what is left after ~he noun phrase is a valid verb
phrase.
Therefore, given the list of words:
r----lr----------~~------1--------~-----I-----------T-------~ ! dve; IDa.len' kie' knigi I lezh8.t I na. pis' mennom i stole I ~ ____ ~ ___________ ~ _______ L ________ ~ ____ L ___________ L __ _____ ~
The first question which need to be asked is:
Does this list have a valid noun phrase at the front?
If so. remove the noun phrase from the list.
The answer to this question will turn out to be yes
(a.coord ing to our gram!l18.r) > removing t.he noun phrase from
the front leaving the list:
~------------------------------------------------~ I lezhat! na! pis'm.ennom; stole : 'L ________ .J ________ .l.. _____________ ._.l.. ________________ .J
The question to be asked at this stage is:
140
Does this list ha.ve va.lid verb phras a.t the front?
If so, remove the verb phrase from the list.
Again the answer to this turns out to be yes, removing the
verb phrase from the list leaves just the empty, list.
So the strategy for parsing a list of words may be
described as follows:
1) Ta.ke the input list.
2) Identify each of the exp.ected eomponents or phra.ses.
one a.t 8. time.
3) Each time a phrase is identified, remove it from the
front of the list.
4) This remainder is used as the list for identifying
the next component.
5) At the very end~ there will be a remainder list
(possibly empty); this will be returned by the
process as left over.
Parsing a sentence is just a special case of parsing
any type of phrase or structure. Therefore. for each sort
of structure
structure) we
(a. sentence> a.
will have a
noun phrase. or any
sep8.ra.te pred ica.te.
other
Ea.ch
predicate will take an input list. and will specify the
conditions under which there is an occurence of that
structure at the front of the list. If the predicate
succeeds, it will return the left over as an input list
after the structure has been stripped off at the front. If
the input list does not meet the conditions. the predicate
shOll ld fa.i L
141
Based on the a.bove understs.nding s. parser comprises
a set of predicate defining validity requirement of
different structures a.nd voc8.bularly definitions.
Let us first consider the predicate which defines
~hat a valid sentence is. As with any other predicate which
pS.rses a structure, there will be an input list and output