ellipse ellipse 0 0 0 30 10
extsurf es_ellipse ellipse 0 0 1
trim es_ellipse_tr es_ellipse 0 3 0 50
trim es_ellipse_tr_tr es_ellipse_tr 0 2 0 30
mkface result es_ellipse_tr_tr 0 1 0 20
set MaxFTol 9.9999999999999995e-08
set MaxETol 9.9999999999999995e-08
set MaxVTol 9.9999999999999995e-08