cdef class Position
cdef class Point(Position)
cdef class Vector(Point)
cdef class CoordSyst

cdef void test(float* f):
  pass


cdef class Position:
  cdef readonly CoordSyst parent
  
cdef class Point(Position):
  cdef void bug(self):
    test(self.parent._matrix)

cdef class Vector(Point):
  cdef void bug(self):
    test(self.parent._matrix)

cdef class CoordSyst:
  cdef float* _matrix