A version space algorithm for learning extracting rules from tree-structured documents. Resulting hypotheses are called "tag tree patterns". A Mapping from tag tree patterns to statements in the XPath language is defined.
J. Weyn, D. Durran, and R. Caruana. Journal of Advances in Modeling Earth Systems, 11 (8):
2680--2693(2019)\_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2019MS001705.