Node Query Preservation for Deterministic Linear Top-Down Tree Transducers

Kazuki Miyahara, Kenji Hashimoto, Hiroyuki Seki
2013 Electronic Proceedings in Theoretical Computer Science  
This paper discusses the decidability of node query preservation problems for XML document transformations. We assume a transformation given by a deterministic linear top-down data tree transducer (abbreviated as DLT^V) and an n-ary query based on runs of a tree automaton. We say that a DLT^V Tr strongly preserves a query Q if there is a query Q' such that for every document t, the answer set of Q' for Tr(t) is equal to the answer set of Q for t. Also we say that Tr weakly preserves Q if there
more » ... s a query Q' such that for every t_d in the range of Tr, the answer set of Q' for t_d is equal to the union of the answer set of Q for t such that t_d = Tr(t). We show that the weak preservation problem is coNP-complete and the strong preservation problem is in 2-EXPTIME.
doi:10.4204/eptcs.134.4 fatcat:rljnbnajljaiblaqoulbizqk64