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

% --- start of displayed preamble in the book ---
input metaobj
% --- end of displayed preamble in the book ---
defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
setObjectDefaultOption("Tree")
("hideleaves")(true);
t:=T_(new_Circle(btex foo etex))
(new_HFan_(1cm,0)("filled(true)"),
Tf,
_T(new_RBox(btex bar etex))
(new_HFan(1cm,0))
)
("Dalign(center)");
Obj(t).c=origin;
draw_Obj(t);
endfig;
end;