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

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

% --- end of displayed preamble in the book ---
% graphic converted to gray in book using 'color2gray'
defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
defaultscale:=1.4; u=1pt;
picture p,q; gap:=18u;
for i := 0 upto 6:
z[i]=(0u,i * gap * u);
endfor;
draw z0--z6;
dotlabels.lft(0,1,2,3,4,5,6);
q=thelabel.urt(btex Poly\TeX etex ,z0);
draw q;
draw q reflectedabout(z0,z0+(2u,0));
draw q shifted(0,gap) withcolor red;
fill bbox q shifted(0,2*gap*u)
withcolor green;
draw q shifted(0,2*gap*u)
withcolor white;
draw q scaled 2 shifted(0,5*gap*u);
p=q rotatedabout(z0,45);
draw p shifted(10u,3*gap*u);
draw bbox currentpicture
withcolor green;
endfig;
end;