Rational power series in several noncommuting variables and the Skolem–Mahler–Lech theorem

We generalize the Skolem–Mahler–Lech theorem for rational power series in several noncommuting variables having a slender support. This generalization gives a connection between the Skolem–Mahler–Lech theorem and the characterization of slender regular languages proved independently by Păun and Salomaa and by Shallit.