TrUDucer: Transforming to Universal Dependencies using tree transducers
TrUDucer is a software for transforming dependency treebanks from one schema to another, especially to Universal Dependencies. The conversion rules are simple to write and the formalism guarantees that all transformations yield valid tree structures.
You can get the source from the git repository @gitlab.
Read the paper: Dependency Schema Transformation with Tree Transducers – presented at the First Workshop on Universal Dependencies.
Section 4 as well as the example rule file describes the rule format.
If you have questions regarding the software, send us a mail; the addresses are in the paper.