parabola parabola 0 0 0 30
extsurf es_parabola parabola 0 0 1
trim es_parabola_tr es_parabola 0 50 0 50
trim es_parabola_tr_tr es_parabola_tr 0 40 0 40
mkface result es_parabola_tr_tr 0 30 0 30
set MaxFTol 9.9999999999999995e-08
set MaxETol 9.9999999999999995e-08
set MaxVTol 9.9999999999999995e-08