%R 10.14232/actacyb.23.1.2017.12 %N 1 %J Acta Cybernetica %X In 2003 we showed that right-linear systems of equations over regular expressions, when interpreted in a category of trees, have a solution whenever they enjoy a specific property that we called hierarchicity and that is instrumental to avoid critical mutual recursive definitions. In this note, we prove that a right-linear system of polynomial endofunctors on a cocartesian monoidal closed category which enjoys parameterized left list arithmeticity, has an initial algebra, provided it satisfies a property similar to hierarchicity. %L eprints3952 %D 2017 %A Anna Labella %A Rocco De Nicola %I Institute of Informatics, University of Szeged %V 23 %O SCOPUS ID: 2-s2.0-85020128814 %P 191-201 %T Initial Algebra for a System of Right-Linear Functors