Expanding the U niversal D ependencies A ncient H ebrew Treebank with Constituency Data (2025)

Abstract: This paper presents an effort to expand the annotation pipeline for the Ancient Hebrew Universal Dependencies treebank to make use of additional data, resulting in the addition of over 4000 sentences and roughly 100K words to the released treebank. The resulting treebank contains 5500 sentences and 145K words and the incorporation of converted constituency data has resulted in an annotation process which requires manual intervention in only around 15-20% of sentences, even in previously unseen genres.

## data sources the data for this project comes from two sources: the biblia hebraica stuttgartensia amstelodamensis (bhsa) and the macula project, both of which annotate the same underlying text. each corpus contributes valuable but incomplete data to the task of producing a ud treebank. the bhsa @xcite provides extensive morphological annotation of the text, and some light semantic annotation. its syntactic annotations, however, are extremely limited, with the structure of most sentences being restricted to a two-layer constituency tree (phrases and clauses), as shown in figure 1 . deriving slightly more detailed trees from the bhsa data is possible foot_0 , but @xcite nonetheless ended up building a system that was much closer to a parser than to a treebank converter. in contrast, macula (clear bible, 2022), which was released after @xcite , has full syntactic information up to the clause level, as shown in figure 2 . however, for more complex sentences, it often leaves the upper layers underspecified, such that each clause is fully annotated, but the relations between clauses are not, as shown in figure 3 . fortunately, some of bhsa's more semantic features can help fill this gap. one of the most important is a feature called txt, which marks the "level" of the text, in particular distinguishing between narrative, quotations, and quotations embedded within quotations, which is usually sufficient to resolve s pp/time ‫ב‬ ‫רשׁית‬ vp/pred ‫ברא‬ np/subj ‫אלהי‬ pp/objc ‫את‬ ‫ה‬ ‫שׁמי‬ ‫ו‬ ‫את‬ ‫ה‬ ‫אר‬ ְ ‫האר‬ ‫ואת‬ ‫השׁמי‬ ‫את‬ ‫אלהי‬ ‫ברא‬ ‫ברשׁית‬ ‫אר‬ 'arets land subs ‫ה‬ ha the art ‫את‬ 'et acc prep ‫ו‬ ve and conj ‫שׁמי‬ shamayim sky subs ‫ה‬ ha the art ‫את‬ 'et acc prep ‫אלהי‬ 'elohiym god subs ‫ברא‬ bara' created verb ‫רשׁית‬ reshiyt beginning subs ‫ב‬ be in prep " in the beginning, god created the sky and the land." figure 1 : the syntax tree and gloss of genesis 1:1, as given by the bhsa (the source used for prior work). phrase nodes are marked with both their category and their function label (here, "object", "subject", "predicate", and "time"). the attachment of clauses which are complements of speaking verbs or are simply coordinated. (other types of subordination present further challenges, which are discussed below.) 3 methodology @xcite used constraint grammar (cg) @xcite as the basis for the following pipeline: rule extraction this script converts the constituency structure of macula into a dependency structure. each node which has multiple children (apart from the top-level sentence node) has attributes which specify which child is the head and what parsing rule generated the node. for each such node, the head is set as the parent of all the other children, and the children receive the rule name as a tag. this process is depicted in figure 6 . this step is substantially simpler than what often appears in other conversion projects, since it only requires a tree traversal to collect all the relations without needing a set of heuristics to identify the heads at each level @xcite @xcite . alignment and arc projection this step determines the correspondences between word ids in bhsa and macula. since the two corpora represent the same underlying text, this is trivial at the sentence level, but presents some challenges at the word level due to differences in tokenization, some of which are shown in (1). here we see the two most frequent divergences: macula treats the locative suffix as a separate unit, unlike bhsa and ud, and the syntax tree of genesis 1:1, as given by macula (the source added in this work). labels in italics are the names of the parsing rules that generated the nodes. the corresponding gloss can be found in figure 1 . bhsa does not treat pronominal suffixes as separate units, unlike macula and ud. the alignment script applies a set of rules describing these divergences to the two texts until it achieves an exact match. if such a match is not found, it reports the sentence to the developer for review. having generated these alignments, the script converts the constituency structure of the macula nodes into dependency arcs between bhsa words. to do this, it takes the head of each phrase node (which macula specifies) and adds an arc from it to the head of each of its siblings, using the rule name as the arc label. each word is then identified with all the phrases it is the head of, producing a dependency tree between words. this process is depicted in figure 6 . ## annotation decisions in the process of revising the treebank, there were hundreds of local changes, such as the modifier attachment discussed above, and a handful of larger systematic ones. in this section, we present three of the latter kind: the introduction of fixed expres-sions, a change in the tokenization guidelines relating to quotations, and the use of the expletive pronoun relation. further details about the annotation decisions of the treebank in general can be found in the ud documentation for ancient hebrew at https:// universaldependencies.org/hbo/ and particularly the documentation of syntactic relations at https://universaldependencies.org/hbo/ dep/ . ## treebank statistics this project has roughly quadrupled the total size of the ancient hebrew treebank. the exact numbers are given in half of the added data (exodus and leviticus) was included in the 2.16 release of universal dependencies. the other half (numbers and deuteronomy) will be included in 2.17. ## conclusion in this paper we have presented an effort to expand the universal dependencies ancient hebrew treebank by converting an existing partial constituency treebank. this process revealed various inconsistencies and areas for improvement in the existing annotations, which have now been fixed. in addition, it has greatly reduced the amount of manual effort required to produce new trees, since the accuracy of the parser is now high enough that a typical tree can be simply validated rather than leading to further debugging of the parser. the treebank now includes approximately a quarter of the source text, and we intend to apply this process to annotate the remainder.