![Page 1: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/1.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Prague Dependency Treebank 2.0
Zdeněk ŽabokrtskýDept. of Formal and Applied Linguistics
Charles University, [email protected]
![Page 2: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/2.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 3: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/3.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Introduction
treebank syntactically annotated corpus (“bank” of syntactic trees)
Prague Dependency Treebank collection of linguistically annotated Czech texts (2MW), software tools and documentation morphological and surface- and deep-syntactic dependency-oriented sentence analyses
![Page 4: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/4.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
About Czech
western group of Slavic languages
rich inflectional morphology
(relatively) free word order language
Latin alphabet extended with accents
(příliš žluťoučký kůň)
spoken in the Czech republic
10+ million speakers
![Page 5: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/5.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Historical backgroundand development of PDT
1920’s – Prague Linguistic Circle founded
1930-50’s – influential dependency-oriented works of
Lucien Tesniere and Vladimír Šmilauer
mid 1960’s – Petr Sgall’s Functional Generative
Description
1992 – Penn Treebank
1994 – Czech National Corpus
1995 – PDT started
1998 – PDT 0.5 pre-release
2001 – PDT 1.0 released by LDC
2006 – PDT 2.0 to be released by LDC
![Page 6: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/6.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 7: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/7.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Layered annotation scheme
tectogrammatical layersurface-syntactic dependency tree
analytical layersurface-syntactic dependency tree
morphological layermorphological lemma and tag associated with each token
word layeroriginal text, segmented on word boundaries
He would have gone intoforest.
![Page 8: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/8.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
M-layer
sentence represented as a sequence of tokens each token lemmatized and tagged (attributes lemma and tag)15-character long positional morphological tag
1. (main) POS 2. detailed POS 3. gender 4. number 5. case ...
![Page 9: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/9.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
A-layer (1)- nodes and edges
sentence represented as a rooted ordered tree with labeled nodes and edges
edges labeled with analytical functions:
dependency relations (Sb, Obj, Adv, Atr)non-dep. relations (Coord)auxiliary (functional) nodes (AuxP for prepositions, AuxC for subordinating conjunctions...)
special treatment of coordination constructions
![Page 10: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/10.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
A-layer (2)- coordination
intricate interplay between dependency and coordination relations
PDT solution: both conjuncts (members of coordination) and shared modifiers attached below the coordination conjunction (but distinguished from each other by a special attribute is_member)
direct parent vs. effective parent:
M M
![Page 11: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/11.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
T-layer (1) - nodes
t-nodescomplex typed feature structuresnodes represent autosemantic wordsfunctional words do not have nodes of their ownartificially added nodes (e.g. for pro-drops)
node attributestectogrammatical lemmadependency relation – functor and subfunctorgrammateme attributes (representing morphological meanings)attributes for topic-focus articulationattributes for coreference relations
![Page 12: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/12.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
T-layer (2) - dependency relations
according to FGD, two types of functorsactants (arguments)
ACT – actorPAT – patientADDR – addresseeEFF – effectORIG - origin
free modifiers (adjuncts) various types of temporal modifiers - TWHEN, TTIL, TSIN...spatial and directional modifiers – LOC, DIR1, DIR2, DIR3MEANS, BENeficiary, CAUSe, REGard, EXTent, MATerial, CONDition...
additional functors for representing non-dependency relations coordinations – CONJ, DISJ, ADVS ... appositions – APPS parenthetical constructions - PAR expressions in foreign language - FPHR
![Page 13: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/13.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
T-layer (3) - valency
all occurrences of all verbs in t-trees interlinked with the valency lexicon PDT-VALLEXindividual valency frames roughly corresponds to individual senses of the given verbvalency frame ~ a sequence of frame slots, for each of which its functor, obligatority and its possible surface realizations are specified
![Page 14: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/14.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
T-layer (3) - coreference
two types of coreference according to FGD grammatical (verbs of control, relative clauses, reflexive pronouns...) textual (personal pronouns, incl. elided ones)
coreference in PDT binary relation between t-nodes depicted as a “non-tree” arc (arrow)
![Page 15: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/15.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
T-layer (4) - grammatemes
grammatemes t-node attributes representing morphological meanings
motivation
number for nouns, tense for verbs, degree for adjectives, deontic/verb/sentence modality ...
Peter met her youngest brother. Peter will meet her young brothers.
PeterACT
meetPREDtense=ant brother
PATnumber=sg
#PersPronAPP
youngRSTRdegree=sup
PeterACT
meetPREDtense=post brother
PATnumber=pl
#PersPronAPP
youngRSTRdegree=pos
Peter met her youngest brother. Peter will meet her young brothers.
PeterACT
meetPREDtense=ant brother
PATnumber=sg
#PersPronAPP
youngRSTRdegree=sup
PeterACT
meetPREDtense=post brother
PATnumber=pl
#PersPronAPP
youngRSTRdegree=pos
![Page 16: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/16.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
T-layer (5) - node typing
presence/absence of a given attribute? the need for node typing
two-level hierarchy of t-layer node types used in PDT 2.0:
tectogrammatical node
com plex atom qcom plexlistcoap dphrfphrroot
semanticadjectives
semanticadverbs
semanticverbs
semantic nouns
denotativen.denot
(number,gender)
pronominal
indefiniten.pron.indef
(number,gender,person,indeftype)
definiten.quant.def
(number,gender,numertype)
quantificative
definitenegationn.denot.neg
(number,gender,negation)
demonstrativen.pron.def.demon
(number,gender)
personaln.pron.def.pers
(number,gender,person,politeness)
tectogrammatical node
com plex atom qcom plexlistcoap dphrfphrroot
semanticadjectives
semanticadverbs
semanticverbs
semantic nouns
denotativen.denot
(number,gender)
pronominal
indefiniten.pron.indef
(number,gender,person,indeftype)
definiten.quant.def
(number,gender,numertype)
quantificative
definitenegationn.denot.neg
(number,gender,negation)
demonstrativen.pron.def.demon
(number,gender)
personaln.pron.def.pers
(number,gender,person,politeness)
![Page 17: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/17.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Interlinking the layers
any unit at any layer has a PDT unique ID
neighboring layers connected by top-down pointers
![Page 18: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/18.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 19: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/19.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Sources of text
texts provided by the Czech National Corpus
7000 articles (or article fragments) from Czech newspapers and journals:
Lidové noviny (daily newspapers) Mladá fronta Dnes (daily newspapers) Českomoravský profit (business weekly) Vesmír (scientific journal)
![Page 20: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/20.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Amount of annotated data
m-layer data1.96 MW in 116 kS
a-layer data (75 % of m-layer)1.5 MW in 88 kS
t-layer data (59 % of a-layer)0.8 MW in 49 kS
![Page 21: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/21.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Division into files
1 XML file per document and annotation layer
![Page 22: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/22.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Train/test data
train : devtest : evaltest = 8 : 1 : 1
![Page 23: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/23.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Full vs. sample data
sample data 500 sentences a freely available subset of the full data converted also to HTML (can be viewed in any WWW browser, no tree editor needed)
the whole PDT 2.0 except for the full data (but including sample data, all tools, docs, and sample data) is available on the web
the full data will be available only to the licensed users who obtain the CD from the Linguistic Data Consortium
![Page 24: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/24.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 25: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/25.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Tree editor TrEd
general customizable tree editor implemented in Perl the main editing and browsing tool in the PDT project
![Page 26: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/26.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Batch processing of the data
btred – batch processing version of tred
ntred – networked (parallelized) version of btred
$ btred -TNe 'print "$this->{t_lemma}\n" if $this->parent==$root and grep{$_->{functor}=~/^DIR/} $this->children()‘ data/sample/*.t.gz -q
![Page 27: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/27.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Netgraph
client-server application for on-line PDT search implemented in Java
![Page 28: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/28.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Tools for post-annotation consistency checking
hundreds of btred scripts of various types:
technical tests e.g. each sentence contains at least one token all identifiers are unique, all referred identifiers exist...
m-layer tests locative (6th case) cannot occur without a preposition improbable word forms (e.g. imperatives haš, tel)
a-layer testsnot more than one subject in a clauseattributes (afun Atr) should not appear directly below verbs
t-layer testssurface forms of verb arguments match the specifications in the valency lexiconrelative pronouns in relative clauses should be in agreement with their antecedent (in the sense of grammatical coreference)
![Page 29: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/29.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Tools for automatic annotation
chain of tools for automatic text processing (from a raw text to a-layer trees):
1. sentence segmentation and tokenization
2. morphological analysis
3. morphological disambiguation
4. dependency parsing (adapted Collins)
5. analytical function assignment
![Page 30: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/30.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Tools for format conversions
conversion not only between PDT data formats, but also from other treebanks’ formats constituency trees from Negra in TrEd:
![Page 31: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/31.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 32: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/32.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
PDT 2.0 Documentation
PDT Guide overview of all parts of PDT 2.0 mirrors the directory structure of the PDT 2.0 CD-ROM
Annotation guidelines m-layer (~100 pages) a-layer (~ 250 pages) t-layer (~ 800 pages)
Publications conference and journal papers, technical reports, theses ...
Technical documentation (software tools and data formats)
![Page 33: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/33.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 34: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/34.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Outline of the talk
Introduction
Layers of annotation
Data
Software tools
Documentation
Tour through the CD-ROM
Final remarks
![Page 35: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/35.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Want to experiment with...
tagging ? dependency parsing ? semantic-role labeling ? frame semantics ? word-sense disambiguation ? anaphora resolution ? information structure ? ...
Use PDT 2.0,it’s all there !!!
![Page 36: Http://ufal.mff.cuni.cz/pdt2.0 PDT 2.0 Prague Dependency Treebank 2.0 Zdeněk Žabokrtský Dept. of Formal and Applied Linguistics Charles University, Prague](https://reader035.vdocument.in/reader035/viewer/2022081513/56649e025503460f94aec035/html5/thumbnails/36.jpg)
http://ufal.mff.cuni.cz/pdt2.0
PDT 2.0
Annotation scheme not limited to Czech
T-layer in English T-layer in German A-layer in German
A-layer in Arabic A-layer in Slovene A-layer in Romanian