### Classifying bicrossed products of two Sweedler's Hopf algebras

We continue the study started recently by Agore, Bontea and Militaru in “Classifying bicrossed products of Hopf algebras” (2014), by describing and classifying all Hopf algebras $E$ that factorize through two Sweedler’s Hopf algebras. Equivalently, we classify all bicrossed products ${H}_{4}\bowtie {H}_{4}$. There are three steps in our approach. First, we explicitly describe the set of all matched pairs $({H}_{4},{H}_{4},\u25b9,\u25c3)$ by proving that, with the exception of the trivial pair, this set is parameterized by the ground field $k$. Then, for...