  We extend some results of Marmi--Moussa--Yoccoz on the cohomological
equations and local conjugacy classes of interval exchange maps of restricted
Roth type.
  In particular, we answer a question of Krikorian about the codimension of the
local conjugacy class of self-similar interval exchange maps associated to the
Eierlegende Wollmilchsau and the Ornithorynque.
