tracingall; tracingonline:=0;
%path p; p=(1,-8)..(3,-7.5)..(5.5,-6)..(7,-4)..(8,-1.5);
%pausing:=1;
%%pickup pencircle scaled 16;
%pickup makepen(p..(reverse p yscaled -1)..(p scaled -1)..(reverse p xscaled-1)..cycle);
%draw (0,7.7)..(10,0)..(20,7.7);
%pausing:=0;
pickup razor scaled 10;
draw (6,1){up}..bounded..(13.5,55)..bounded..{down}(21,1);
%draw (6,1){up}..(13.5,25)..{down}(21,1);
%draw (6,1){up}..(16,19)..(25,1);
edges pic[];
pic1=currentpicture;
pic2=currentpicture shifted(30,0);
pic3=currentpicture shifted(60,0);
cull pic1 by (-infinity,1);
cull pic2 by (-infinity,2);
cull pic3 by (-infinity,3);
pic0=pic1+pic2+pic3;
showall pic1,pic2,pic3;
openit;
display pic0 inwindow 0;
stop "and...";