box b 10 10 10
copy b bf
foreach e [explode b e] {
  nurbsconvert ne $e
  eval mkvolume s ne [explode bf f]

  savehistory mv_hist
  modified m mv_hist ne

  mkcurve cur m
  if {![regexp "BSplineCurve" [dump cur]]} {
    puts "Error: Boolean Operation took the second face"
  }

  # make the shape periodic in all directions
  makeperiodic res s -x 10 -y 10 -z 10

  savehistory h
  modified me h m

  # get twins for the edge
  periodictwins twins me

  checknbshapes twins -edge 2 -m "Periodic twins" -t
  mkcurve c_me me
  if {![regexp {Basis curve :\n([^ \n]*)} [dump c_me] full e_type]} {
    puts "Error: Unable to get the type"
  }

  foreach t [explode twins e] {
    mkcurve c_$t $t
    if {![regexp {Basis curve :\n([^ \n]*)} [dump c_$t] full t_type]} {
      puts "Error: Unable to get the type"
    }
    if {$e_type != $t_type} {
      puts "Error: Twins have different geometries"
    }
  }
}