Regular Sets of Descendants for Constructor-based Rewrite Systems Pierre Rety Keywords : term rewriting, tree automata. Abstract : Starting from the regular tree language $E$ of ground constructor-instances of any linear term, we build a finite tree automaton that recognizes the set of descendants $R^*(E)$ of $E$ for a constructor-based term rewrite system whose right-hand-sides fulfill the following three restrictions\,: linearity, no nested function symbols, function arguments are variables or ground terms. Note that left-linearity is not assumed. We next present several applications.