  We present a novel approach to sentence simplification which departs from
previous work in two main ways. First, it requires neither hand written rules
nor a training corpus of aligned standard and simplified sentences. Second,
sentence splitting operates on deep semantic structure. We show (i) that the
unsupervised framework we propose is competitive with four state-of-the-art
supervised systems and (ii) that our semantic based approach allows for a
principled and effective handling of sentence splitting.
