polyline p 0 0 0 11 0 0 11 0 4 10 0 4 10 0 3 9 0 2 8 0 2 7 0 3 7 0 4 4 0 4 4 0 3 3 0 2 2 0 2 1 0 3 1 0 4 0 0 4 0 0 0
mkplane f p
prism s f 0 5 0

OFFSETSHAPE 1.8 {} $calcul $type

checkprops result -v 954.256

checknbshapes result -shell 1
