verbatimtex
\input latex.pre
etex

beginfig(1);
numeric u;
u=5mm;

path region, regiona, regionb;
region = fullcircle xscaled  7u yscaled 4.3u;
regiona = fullcircle xscaled  3.4u yscaled 2.3u shifted (-1.1u,0);
regionb = fullcircle xscaled  3.4u yscaled 2.6u shifted (0.8u,0);

fill regiona withcolor 0.8white;
fill regionb withcolor 0.8white;

draw region;
draw regiona;
draw regionb;

label(btex $A$ etex, (-1.4u,1.55u));
label(btex $B$ etex, (1.0u,1.7u));
label(btex $AB$ etex, (-0.15u,0u));


endfig;
bye
