Sukkah 20: When a Mat Has a Wall

In the ongoing discussion of the mats and their acceptability as schach, we find some rabbinic interlude, which brings us to: Who's Who: Rabbi Hiya. Plus, more on the mats themselves. The question of whether they are acceptable continues to revolve around the potential they have to be rendered impure - regardless of the variety of materials that can be used to make a mat. Also, a trans-Babylonia/Israel exchange that conclusively answers the question of the permissibility of the mats. Almost.