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Parsing Akkadian Verbs in Prolog

Aaron MacksBrandeis University

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Overview

• Akkadian• Prolog• Parsing using Prolog• Java and web interface• Examples

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Akkadian

• Verbal system based on three radicals, R1-R2-R3, commonly from the verb paräsum: P-R-S(to divide)

• Any one or more radical can be ‘weak’ from letters in the earlier Proto-Semitic which dropped out or a soundless Aleph(’), i.e. elûm ’-L-weak

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Verbs in Akkadian

• Description of a conjugated verb has six parts– Stem: P-R-S– Stem type: G, D, N, $, Xt, Xn, Xtn– Person: 1st, 2nd, 3rd

– Gender: M, F or common– Number: Singular or plural– Tense: Preterite, durative, perfect, imperfect,

precative or vetitive

• Ex: iprus -> PRS, 3CS, G-Preteriteiqabbû-ma -> QB`, 3MP, G-Durative

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Overview

• Akkadian• Prolog• Parsing using Prolog• Java and web interface• Examples

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Prolog Introduction

• Logical programming language, emerged in the 1970’s, ISO standard in 1996

• Modern implementations can accept:– Declarations:

• father(X,Y) :- male(X),parent(X,Y).– DCG(definite clause grammar) rules:

• s(X,Y) --> [c].• s(X,Y) --> X, s(X,Y), Y.• s --> s([a],[b]).

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DCGs Continued• s([a,a,a,c,b,b,b],[]).

– yes• s([a,a,a,c,b,b,b,d,d], T).

– T = [d, d] • s([a,a,a,c,b,b|N],T).

– N = [b|_G293]T = _G293

• s([n,i],[e], O, []).– O = [c] ;– O = [n, i, c, e] ;– O = [n, i, n, i, c, e, e]

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Overview

• Akkadian• Prolog• Parsing using Prolog• Java and web interface• Examples

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Program Flow

?- verb(A,B,C,Type,[i,p,r,u,s]).• Prolog call to parse iprus, with A,B, and C bound to

the stem and Type a string of the verb type

• verb calls: G, D, N, G-suffix, D-suffix, N-suffix

• Each of G, D, and N call: preterite, perfect, durative, imperfect, vetitive, and precative

• Each of the tenses call: strong, first-weak, second-weak, and third-weak. Some also have A, E, N, or W classes as well.

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Sample

?- verb(A,B,C, Type, [ii,p,u,s],[]).

verb(Ca, Cb, Cc, ['G'|Type], Verb) :- [gstem],g(Ca, Cb, Cc, Type, Verb, []).

g(Ca, Cb, Cc, ['Preterite'|Type], Verb, Suff) :- gpret(Ca, Cb, Cc, Type, Verb, Suff).

gpret(Ca, Cb, Cc, [‘First Aleph’|Type], Verb, Suff) :- fstwgpret(Ca, Cb, Cc, Verb, Suff, Type).

fstweakgpred([@], Cb, Cc, [3, c, s]) --> [ii], Cb, vs, Cc.

• A = @

B = p

C = s

Type = ['G', 'Preterite', 'First Aleph', 3, c, s]

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Rule Count

• The body of the parser consists of 601 DCG rules: – 21 Vowel rules– 4 String-to-PlNF– 47 Suffix– Remaining 529 in the stem definitions:

• 239 - G-Stem• 193 - D-Stem• 93 - N-Stem

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DCG Rules

• Simple:– fstweakgpred([@], Cb, Cc, [3, c, s]) --> [ii], Cb, vs, Cc.

• Derivative– fstweakgpred([@], Cb, Cc, [2, f, s])--> fstweakgpred([w], Cb, Cc, [2, m, s]), [ii].

• Complex– ndur([Ca], Cb, Cc, ['Third Weak'|Type], Verb, Suff) :-trdwgdur([Ca,Ca], Cb, Cc, Type, Verb, Suff).

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Overview

• Akkadian• Prolog• Parsing using Prolog• Java and web interface• Examples

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Flow

• Web forms send data to parseAkk class

• parseAkk reformats data, sends to akkadian class, executes Prolog code

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Extra Java Features

• * expansion for parsing

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More Java Features

• ‘Any’ keyword for generation

• Problems:– Generates all possible vowel variations– Adds the -ma suffix– Can create large files [prs, Any]

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Overview

• Akkadian• Prolog• Parsing using Prolog• Java and web interface• Examples

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Parsing Examples

?- verb(A,B,C,T, [i,p,r,u,s]).A = pB = rC = sT = ['G', 'Preterite', 3, c, s] ;

?- verb(p,r,s,[‘G’,’Preterite’, 2,c,p],Plnf).Plnf = [t, a, p, r, a, s, aa] ;Plnf = [t, a, p, r, e, s, aa] ;Plnf = [t, a, p, r, i, s, aa] ;Plnf = [t, a, p, r, u, s, aa] ;

?- verb(p,r,s,[S,’Preterite’, 2,c,p],Plnf).

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Examples 2

• Stem = 'G'

P = [i, p, r, a, s] ;• Stem = 'G'

P = [i, p, r, e, s] ;• Stem = 'G'

P = [i, p, r, i, s] ;• Stem = 'G'

P = [i, p, r, u, s] ;• Stem = 'D'

P = [u, p, a, r, r, i, s] ;

• Stem = 'N’P = [i, p, p, a, r, i, s] ;

• Stem = 'N'P = [i, p, p, e, r, i, s] ;

• Stem = 'N'P = [i, p, p, i, r, i, s] ;

• Stem = 'N'P = [i, p, p, u, r, i, s] ;

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Suffix Examples

• imhur$inaati– G Preterite 3 c s Accusative 3 f p

• iddin$inaa$im– d-d-n--G Preterite 3 c s Dative 3 f p– n-d-n--G Preterite First N 3 c s Dative 3 f p– @-d-n--G Durative First Aleph 3 c s Dative 3 f p– w-d-n--G Durative First W Stative 3 c s Dative 3 f p– n-d-n--G Precative First N 3 c s Dative 3 f p– @-d-n--D Imperative First Weak 2 m s Davie 3 f p

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Web Examples