# GF Resource Grammar Library v. 1.1

Author: Aarne Ranta <aarne (at) cs.chalmers.se>
Last update: Thu Apr 19 23:35:29 2007

The GF Resource Grammar Library defines the basic grammar of ten languages: Danish, English, Finnish, French, German, Italian, Norwegian, Russian, Spanish, Swedish. A still incomplete implementation for Arabic is also included.

New in Version 1.1

- Simpler APIs using overloading:
  - Constructors: almost all trees in a category `C` can be built by the function `mkC`.
  - Combinators: cross-cut grammatical functions: predication, application, modification, coordination.
  - Symbolic: noun phrases with mathematical symbols.

An example of use is `logic`. The API of version 1.0 remains valid and can be used in combination with this.

- Some new functions.
- Bug fixes.

## Authors

Inger Andersson and Therese Soderberg (Spanish morphology), Nicolas Barth and Sylvain Pogodalla (French verb list), Ali El Dada (Arabic modules), Janna Khegai (Russian modules), Bjorn Bringert (many Swadesh lexica), Carlos Gonzalía (Spanish cardinals), Harald Hammarström (German morphology), Patrik Jansson (Swedish cardinals), Andreas Priesnitz (German lexicon), Aarne Ranta.

We are grateful for contributions and comments to several other people who have used this and the previous versions of the resource library, including Ludmilla Bogavac, Ana Bove, David Burke, Lauri Carlson, Gloria Casanellas, Karin Cavallin, Robin Cooper, Hans-Joachim Daniels, Elisabet Engdahl, Markus Forsberg, Kristofer Johannisson, Anni Laine, Peter Ljunglöf, Saara Myllyntausta, Wanjiku Ng'ang'a, Jordi Saludes.

## License

The GF Resource Grammar Library is open-source software licensed under GNU General Public License. See the file LICENSE for more details.

## Scope

Coverage, for each language:

- complete morphology
- lexicon of the ca. 100 most important structural words
- test lexicon of ca. 300 content words (rough equivalents in each language)
- list of irregular verbs (separately for each language)
- representative fragment of syntax (cf. CLE (Core Language Engine))
- rather flat semantics (cf. Quasi-Logical Form of CLE)

Organization:

- top-level (API) modules
- Ground API + special-purpose APIs
- "school grammar" concepts rather than advanced linguistic theory

Presentation:

- tool `gfdoc` for generating HTML from grammars
- example collections

## Quick start

Go to the main directory, compile the grammars, and run a test.

        cd GF/lib/resource-1.0
        make
        make test

This will take quite some time. An alternative is to use the precompiled grammar package `compiled.tgz`. This package has the necessary `gfc` and `gfr` files directly under `GF/lib`.

        GF/lib/alltenses
        GF/lib/mathematical
        GF/lib/multimodal
        GF/lib/present

Do for instance

        cd GF/lib/
        gf
          > i -path=present:prelude present/LangEng.gfc
          > gr -cat=S -number=3 -cf | tb

For more examples, see the Overview slides. The `make` procedure does not make Arabic, but it can be compiled in a similar way as the other languages.

## Encoding

Finnish, German, Romance, and Scandinavian languages are in isolatin-1.

Arabic and Russian are in UTF-8.

English is in pure ASCII.

### The language independent ground API

This API is accessible by both `present` and `alltenses`. The API is divided into a bunch of `abstract` modules. The following figure gives the dependencies of these modules.

The documentation of the individual modules:

- Common: abstract notions with language-indep. implementations
- Cat: the category system
- Noun: construction of nouns and noun phrases
- Adjective: construction of adjectival phrases
- Verb: construction of verb phrases
- Adverb: construction of adverbial phrases
- Numeral: construction of cardinal and ordinal numerals
- Sentence: construction of sentences and imperatives
- Question: construction of questions
- Relative: construction of relative clauses
- Conjunction: coordination of phrases
- Phrase: construction of the major units of text and speech
- Text: construction of texts from phrases, using punctuation
- Idiom: idiomatic phrases, such as existentials
- Structural: a lexicon of structural words
- Lexicon: a lexicon of other common words, for test purposes
- Grammar: the main module comprising all but `Lexicon`
- Lang: the main module comprising both `Grammar` and `Lexicon`

### The language-dependent APIs

- ParadigmsDan: Danish lexical paradigms
- ParadigmsEng: English lexical paradigms
- ParadigmsFin: Finnish lexical paradigms
- ParadigmsFre: French lexical paradigms
- ParadigmsIta: Italian lexical paradigms
- ParadigmsGer: German lexical paradigms
- ParadigmsNor: Norwegian lexical paradigms
- ParadigmsRus: Russian lexical paradigms
- ParadigmsSpa: Spanish lexical paradigms
- ParadigmsSwe: Swedish lexical paradigms

- IrregDan: Danish irregular verbs (very incomplete)
- IrregEng: English irregular verbs
- IrregFre: French irregular verbs
- IrregGer: German irregular verbs
- IrregNor: Norwegian irregular verbs (very incomplete)
- IrregSpa: Spanish irregular verbs
- IrregSwe: Swedish irregular verbs

This is the structure of each language-dependent top module.

- Extra: extra constructs implemented in some languages
- ExtraDan: extra constructs in Danish
- ExtraEng: extra constructs in English
- ExtraFin: extra constructs in Finnish
- ExtraFre: extra constructs in French
- ExtraIta: extra constructs in Italian
- ExtraNor: extra constructs in Norwegian
- ExtraRus: extra constructs in Russian
- ExtraScand: extra constructs in Scandinavian
- ExtraSpa: extra constructs in Spanish
- ExtraSwe: extra constructs in Swedish

- Danish: Danish with all extras
- English: English with all extras
- Finnish: Finnish with all extras
- French: French with all extras
- German: German with all extras
- Italian: Italian with all extras
- Norwegian: Norwegian with all extras
- Russian: Russian with all extras
- Spanish: Spanish with all extras
- Swedish: Swedish with all extras

### Special-purpose APIs

#### Present

The API is the same as for the full ground API, but the compiler has ignored all verb and sentence tenses except the present. Lines ignored in the source files are marked by `--# notpresent`. The result is a smaller and more efficient grammar, which is still sufficient for many applications.

#### Multimodal

The API is the same as for the full ground API, but with modified linearization types of `NP` and `Adv`, and all other categories depending on them: an extra field is added to a demonstrative pointing gesture. Some functions for constructing demonstratives are provided.

- Multi: main module for multimodal dialogue systems

#### Mathematical

- Mathematical: main module for mathematical language
- Predication: predication with verbs, adjectives, etc
- Symbol: symbols and numbers in text

## Using the library

### The compiled version

The simplest way to get the library is to install the precompiled version `lib/compiled.tgz`. Just do

        cd GF/lib
        tar xvfz compiled.tgz

There is no need to link application grammars to the source directories of the library. Use one (or several) of the following packages instead:

- `lib/alltenses` the complete ground-API library with all forms
- `lib/present` a pruned ground-API library with present tense only
- `lib/mathematical` special-purpose API for mathematical applications
- `lib/multimodal` the complete ground-API with demonstratives for multimodal dialogue applications

### Linking applications to libraries

Typically, open one of

- `GrammarX` for just syntax
- `LangX` for both syntax and a small lexicon
- `X` (e.g. `English`) for syntax, lexicon, and language-dependent extensions

Usually you also need your own lexicon, and hence have to open

- `ParadigmsX` for lexicon-building functions

It is advisable to use the bare package names in paths pointing to the libraries. Here is an example, from `examples/dialogue/LightsEng.gf`:

        --# -path=.:alltenses:multimodal:prelude

To reach these directories from anywhere, set the environment variable `GF_LIB_PATH` to point to the directory `GF/lib/`. For instance, I have the following line in my `.bashrc` file:

        export GF_LIB_PATH=/home/aarne/GF/lib

The `mathematical` API shares modules with `present`. It is therefore not a good idea to use it in combination with `alltenses`.

### Using the libraries as top-level grammars

If you have done `make` in `lib/resource-1.0`, you will have a file `langs.gfcm`. This file can be used with fast startup for tasks such as treebank generation:

        > i -nocf langs.gfcm
        > gr -cat=S -cf -number=10 | tb

The `-nocf` flag saves startup time and memory by preventing the creation of context-free parse grammars. The resource grammar libraries do not support parsing very well. While it is theoretically possible to parse with any GF grammar, the resource grammars are so abstract and complex that building the actual parser in memory may just need too much resources to succeed.

An exception is `LangEng`. It is actually feasible to parse with both `alltenses/LangEng` and `present/LangEng` - the latter being much faster than the former. The `-fcfg` flag (fast multiple context-free grammar) must be used:

        p -lang=LangEng -fcfg "this man is old"

Parsing with the `-fcfg` flag takes a few extra seconds the first time during each session, but gets faster at later runs. From GF 2.6, `fcfg` is the default parser of GF and the flag is not needed.

It is also possible to parse in Scandinavian languages (Danish, Norwegian, Swedish) and, with enough memory (`gf +RTS -K512M`), German.

## Example applications

These applications are meant to serve as starting points for new applications, showing how the libraries can be used in typical situations.

### Bronzeage

The examples/bronzeage grammar set implements a language fragment based on the Swadesh list of 200 words. It is useful for things like language training.

### Dialogue

The examples/dialogue grammar set implements the user grammars of some multimodal dialogue system. Its purpose is to serve as a prototype for applications in the TALK project.

### Animals

The examples/animal grammar set implements some queries about animals. Its purpose is to serve as a prototype for example-based grammar writing.

## Known bugs and missing components

Danish

- the lexicon and chosen inflections are only partially verified

English

Finnish

- wrong cases in some passive constructions

French

- multiple clitics (with V3) not always right
- third person pronominal questions with inverted word order have wrong forms if "t" is required e.g. (e.g. "comment fera-t-il" becomes "comment fera il")

German

Italian

- multiple clitics (with V3) not always right

Norwegian

- the lexicon and chosen inflections are only partially verified

Russian

- some functions missing
- some regular paradigms are missing

Spanish

- multiple clitics (with V3) not always right
- missing contractions with imperatives and clitics

Swedish

## More reading

GF Resource Grammar Library (pdf). Printable user manual with API documentation (version 1.0).

Grammars as Software Libraries. Slides with background and motivation for the resource grammar library.

GF Resource Grammar Library Version 1.0. Slides giving an overview of the library and practical hints on its use.

How to write resource grammars. Helps you start if you want to add another language to the library.

Parametrized modules for Romance languages. Slides explaining some ideas in the implementation of French, Italian, and Spanish.

Grammar writing by examples. Slides showing how the method is used.

Multimodal Resource Grammars. Slides showing how to use the multimodal resource library. N.B. the library examples are from `multimodal/old`, which is a reduced-size API.