Boy's surface

Complex_numbers gives some basic functions for complex numbers in OpenSCAD. A complex number is a vector with two entries, the real and the imaginary part. There are functions for complex multiplication and division, complex conjugate and taking real powers of complex numbers.
Rotation_2_point_bar is a single module, it takes two vectors in 3 dimensional space as input and then draws a cylinder between them. This is useful for making grids or meshes. Once the vertices of the mesh are known, one