% --- start of displayed preamble in the book ---
input metaobj
% Circles produced as before

% --- end of displayed preamble in the book ---

  newCircle.a(btex start etex);
  newCircle.b(btex end etex);
  a.c=origin;
  b.c-a.c=(1.5cm,1cm);

defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
ncbox(a)(b)
  "linecolor(blue)","linewidth(1pt)",
  "nodesepA(1cm)","nodesepB(1cm)",
  "boxsize(1cm)";
ncbox(a)(b)
  "linecolor(blue)","linewidth(1pt)",
  "nodesepA(1.3cm)","nodesepB(1.1cm)",
  "boxsize(1.5cm)","linearc(3mm)";
drawObj(a,b);
endfig;
end;