newtype application as a SourceType; instead as a TyConApp.
+NOTE: currently [March 02] we regard a newtype as 'recursive' if it's in a
+mutually recursive group. That's a bit conservative: only if there's a loop
+consisting only of newtypes do we need consider it as recursive. But it's
+not so easy to discover that, and the situation isn't that common.
+
+
%************************************************************************
%* *
\subsection{The data type}