Grammar Implementation with Lexicalized Tree Adjoining Grammars and Frame Semantics Grammar implementation with XMG: Syntax Laura Kallmeyer, Timm Lichte, Rainer Osswald & Simon Petitjean University of Düsseldorf DGfS Fall School, September 19, 2017 SFB 991
Recapitulation of yesterday two meanings of “implementation” two techniques of grammar implementation: metarules versus metagrammar introduction to grammar engineering with XMG Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 2 2
Two kinds of grammar implementation grammar/ linguistic theory “implementation” specifications in accordance with a grammar formalism evaluation of the theory As is frequently pointed out but cannot be overemphasized, an important goal of formalization in linguistics is to enable subsequent researchers to see the defects of an analysis as clearly as its merits; only then can progress be made efficiently. (Dowty 1979: 322) Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 3 3
Two kinds of grammar implementation grammar/ linguistic theory “implementation” specifications in accordance with a grammar formalism “implementation” evaluation grammar resource of the theory computational application Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 4 3
What kind of grammar resource? S tree template NP VP V ⋄ NP lexical insertion anchor repairs Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 5 4
Today XTAG: an example for a manually constructed grammar Examples with XMG: active-passive alternation, wh-movement, multi-word expressions Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 6 5
The XTAG-project was located at the University of Pennsylvania (ca. 1988-2001) grammar (set of tree templates/families) tools (browser, editor, parser, ...) Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 7 6
The XTAG-project was located at the University of Pennsylvania (ca. 1988-2001) grammar (set of tree templates/families) tools (browser, editor, parser, ...) URL: http://www.cis.upenn.edu/~xtag/ [Manual: XTAG Research Group [14]] Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 8 6
The XTAG-project was located at the University of Pennsylvania (ca. 1988-2001) grammar (set of tree templates/families) tools (browser, editor, parser, ...) URL: http://www.cis.upenn.edu/~xtag/ [Manual: XTAG Research Group [14]] the architecture of the XTAG-grammar list of tree templates and tree families Tree Database root form, POS → list of tree templates or Syntactic Database or tree families, list of feature equations inflected form → root form, Morph Database POS, inflectional information Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 9 6
The architecture of the XTAG-grammar Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 10 7
The architecture of the XTAG-grammar Example: Tree template for the declarative transitive verb ( α nx0Vnx1), where ⋄ marks the lexical insertion site: S NP VP V ⋄ NP Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 11 8
The architecture of the XTAG-grammar Example: Tree template for the declarative transitive verb ( α nx0Vnx1), where ⋄ marks the lexical insertion site: S NP VP V ⋄ NP A tree family is a set of tree templates, represents a subcategorization frame, and contains all syntactic configurations the subcategorization frame can be realized in. Example: α nx0Vnx1 ∈ Tnx0Vnx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 12 8
Tree families Example tree families intransitive: Tnx0V tree set containing: base tree, wh-moved subject, imperative, determiner gerund, ... etc. Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 13 9
Tree families Example tree families intransitive: Tnx0V tree set containing: base tree, wh-moved subject, imperative, determiner gerund, ... etc. transitive: Tnx0Vnx1 tree set containing: base tree, wh-moved subject, wh-moved object, imperative, determiner gerund, passive with by , passive without by ... etc. Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 14 9
Tree families Example tree families intransitive: Tnx0V tree set containing: base tree, wh-moved subject, imperative, determiner gerund, ... etc. transitive: Tnx0Vnx1 tree set containing: base tree, wh-moved subject, wh-moved object, imperative, determiner gerund, passive with by , passive without by ... etc. Some figures [Prolo [12]] subcat. group no. of families no. of trees intransitive 1 12 transitive 1 39 ditransitive 1 46 light verb constr. 2 53 . . . . . . . . . TOTAL: 57 1008 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 15 9
The situation: templates ... 12 templates 39 tree templates for intransitive verbs for transitive verbs S S NP VP NP VP V V NP S S NP S NP S NP VP NP VP V V NP ε ε ... ... Basically, XTAG defines a set of 1008 unrelated tree templates. Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 16 10
The situation: templates with features � � α W0nx0V: inv 4 S q wh 3 extr + � � inv 4 agr 2 wh 3 � � 3 + NP wh S r – inv trace 5 agr 2 � � � � agr 2 � � NP VP trace 5 ϵ V ⋄ Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 17 11
The situation: templates with many features See full entries here: http://xmg.phil.hhu.de/index.php/upload/xmg_xtag Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 18 12
Metarules for LTAG Idea from GPSG [10] , later applied to XTAG [2,3,12] tree fragments metarules accumulation metarules core grammar expanded grammar (tree templates) (tree templates) metarules connect tree templates of a tree family Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 19 13
Metarules for LTAG: Example α nx0Vnx1 passivization extraction α nx1Vbynx0 α W0nx0Vnx1 extraction α W1nx1Vbynx0 Tnx0nx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 20 14
Metagrammars for LTAG Candito (1996) [7,8,13] accumulation of descriptions tree fragments tree templates arbitrary disjunction tree families Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 21 15
Metagrammars for LTAG: Properties no deletion, no copying, no recursion declarative, order insensitive The number of minimal models is finite. BUT: the number of minimal models can grow exponentially ( O( n ! ) ) in terms of the number of described nodes. Does it suffice? How to express passivization? Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 22 16
Metagrammar for LTAG: Example α nx0Vnx1 passivization extraction α nx1Vbynx0 α W0nx0Vnx1 extraction α W1nx1Vbynx0 Tnx0nx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 23 17
Metagrammars for LTAG: Passivization S NP VP S V ⋄ PP NP VP P NP V ⋄ NP | = by Tnx0nx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 24 18
Metagrammars for LTAG: Passivization � � VP � � � � � � � � V ⋄ PP VP � � S VP � � � � ∧ ∧ ∨ � � � � P NP V ⋄ NP NP VP V ⋄ � � � � � � by S NP VP S V ⋄ PP | = NP VP P NP V ⋄ NP by Tnx0nx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 25 18
Metagrammars for LTAG: Passivization � � VP � � � � � � � � V ⋄ PP VP � � S VP � � � � ∧ ∧ ∨ � � � � P NP V ⋄ NP NP VP V ⋄ � � � � � � by disjunction S does the trick! NP VP S V ⋄ PP | = NP VP P NP V ⋄ NP by Tnx0nx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 26 18
Metagrammar for LTAG: Classes � VP � � � � � � � � � V ⋄ PP � VP � S VP � � ∨ � � Tnx0Vnx1: ∧ ∧ � � � � P NP V ⋄ NP NP VP V ⋄ � � � � � � by Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 27 19
Metagrammar for LTAG: Classes � VP � � � � � � � � � V ⋄ PP � VP � S VP � � ∨ � � Tnx0Vnx1: ∧ ∧ � � � � P NP V ⋄ NP NP VP V ⋄ � � � � � � by Tnx0Vnx1: Subject ∧ VerbProjection ∧ (Object ∨ by-Phrase) Tnx0Vnx1: nx0V ∧ (Object ∨ by-Phrase) Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 28 19
Metagrammar for LTAG: Classes � VP � � � � � � � � � V ⋄ PP � VP � S VP � � ∨ � � Tnx0Vnx1: ∧ ∧ � � � � P NP V ⋄ NP NP VP V ⋄ � � � � � � by Tnx0Vnx1: Subject ∧ VerbProjection ∧ (Object ∨ by-Phrase) Tnx0Vnx1: nx0V ∧ (Object ∨ by-Phrase) Subject VerbProjection Object by-Phrase nx0V Tnx0Vnx1 Kallmeyer, Lichte, Osswald & Petitjean (HHU Düsseldorf) 29 19
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