Unranked Anti-Unification with Hedge and Context Variables
Alexander Baumgärtner, Temur Kutsia · EPiC series in computing · 2018
In this work we study anti-unification for unranked terms and hedges, permitting context and hedge variables. Hedges are sequences of unranked terms. The anti-unification problem of two hedges s and q is concerned with finding their generalization, a hedge g such that both s and q are instances of g under some substitutions. Context variables are used to abstract vertical differences in the input hedges, and hedge variables are used to abstract horizontal differences. A rule based system in Huet's style will be presented, which computes a set of generalizations of input hedges and records all the differences. The computed generalizations are least general among a certain class of generalizations.