The general ichain structure is for some superclass on the same chain,
but not necessarily the chain head. The later prose already has this
right, but the synopsis at the beginning of the section didn't.
@<type>_n @<slot>_n; \-\\
\} $c$; \-\\
\} $c$; \\
- struct $H$__ichain_$h$ $h$; \\
+ struct $A$__ichain_$h$ $a$; \\
\quad$\vdots$ \-\\
\} $h$; \\
union $B$__ichainu_$i$ $i$; \\
\h'6n'} \fIc\fB;
\h'4n'} \fIc\fB;
\h'4n'\fR...\fB
-\h'4n'struct \fIH\fB__ichain_\fIh\fB \fIh\fB;
+\h'4n'struct \fIA\fB__ichain_\fIh\fB \fIa\fB;
\h'2n'} \fIh\fB;
\h'2n'union \fIB\fB__ichainu_\fIi\fB \fIi\fB;
\h'2n'\fR...\fB