  We give a simple, low resource method to produce order embeddings from
ontologies. Such embeddings map words to vectors so that order relations on the
words, such as hypernymy/hyponymy, are represented in a direct way. Our method
uses sketching techniques, in particular countsketch, for dimensionality
reduction. We also study methods to merge ontologies, in particular those in
medical domains, so that order relations are preserved. We give computational
results for medical ontologies and for wordnet, showing that our merging
techniques are effective and our embedding yields an accurate representation in
both generic and specialised domains.
