#F3----------------------------------------------
polyline p 2 0 0 15 0 0 15 0 20 2 0 20 2 0 0 
profile p p 0 -1 0 1 0 0 f 2 0 l 15 t 0 20 t -5 0 \
t 0 -18 t -5 0 t 0 18 t -5 0
revol p p 0 0 0 0 0 1 180
nexplode p e
blend p p 2 p_8 2 p_24
nexplode p f
depouille result p 0 0 1 p_2 2 0 0 0 0 0 1 \
p_12 3 0 0 0 0 0 1 \
p_3 1 0 0 0 0 0 1

checkprops result -s 3349.7