Free involutive Hom-semigroups and Hom-associative algebras (Q282429)

The word ``Hom-'' usually makes our study become more challenging than classical algebraic structures. For example, until to now we still do not know what a free Hom-associative algebra is. The paper under review provides an answer in this direction: as a final result, the authors get a quite explicit description of free Hom-associative algebra generated by a set under the condition that its unary operation is multiplicative and is an involution.