\starttext
\switchtobodyfont[30pt]
\startMPpage
StartPage ;
unit := 2 * cm ;
%numeric lm, row, col, bm; 
pair  middle;
row := 1; col := 1; 
picture p, q ; p := nullpicture; q := nullpicture;

string l[], lbl;
l[0] := "" ; l[1]:= "2"; 

for i= 0 upto row:
middle := 0.5[((( i * unit) ), ((2 * unit))), ((((i+1) * unit) ), ((2 * unit) ))];
lbl := l[i];
p := thelabel(lbl, middle); 
q := p reflectedabout (0.5[urcorner p, ulcorner p], 0.5[lrcorner p, llcorner p]);
draw q;

endfor
StopPage ;
\stopMPpage
\stoptext