  We summarise the recent theoretical progress in few-body descriptions of the
piNN system. Previous descriptions, both three- and four-dimensional, are shown
to possess serious theoretical inconsistencies. We illustrate how
three-dimensional approaches suffer from renormalisation problems, and how
four-dimensional descriptions contain both overcounting and undercounting of
diagrams. We then show how such theoretical problems have been recently
overcome, leading to new practical few-body equations for the piNN system.
