Abstract :
We give a description in terms of square matrices of the family of group-like algebras with S*id=id*S=uε. In the case that S=id and , this translation take us to Hadamard matrices and, particularly, to examples of bi-Frobenius algebras satisfying S*id=id*S=uε and that are not Hopf algebras. Finally, we generalize some known results on separability and coseparability valid for finite-dimensional Hopf algebras to this special class of bi-Frobenius algebras with S*id=id*S=uε, presenting a version of Maschkeʹs theorem for this family.
