parabola parabola 0 0 0 30
extsurf es_parabola parabola 0 0 1
offset es_parabola_of es_parabola 5
offset es_parabola_of_of es_parabola_of 5
mkface result es_parabola_of_of 0 3 0 40
set MaxFTol 9.9999999999999995e-08
set MaxETol 9.9999999999999995e-08
set MaxVTol 1.0000000000000002e-07