  We provide a characterization of no-iteration distributive laws in terms of
its monads in extensive form only. To do that, it is necessary to take account
of both right and left extension systems. We also give, in this right-left
perspective, characterizations of the 1-cells and 2-cells in $\mathbf{EM}(K)$
and $\mathbf{Kl}(K)$.
