  We present a context-preserving text simplification (TS) approach that
recursively splits and rephrases complex English sentences into a semantic
hierarchy of simplified sentences. Using a set of linguistically principled
transformation patterns, input sentences are converted into a hierarchical
representation in the form of core sentences and accompanying contexts that are
linked via rhetorical relations. Hence, as opposed to previously proposed
sentence splitting approaches, which commonly do not take into account
discourse-level aspects, our TS approach preserves the semantic relationship of
the decomposed constituents in the output. A comparative analysis with the
annotations contained in the RST-DT shows that we are able to capture the
contextual hierarchy between the split sentences with a precision of 89% and
reach an average precision of 69% for the classification of the rhetorical
relations that hold between them.
