Someone smarter than me could probably make a joke about normals (from geometry)
@vaporeon_ amy and holly are linearly independent and span the monorail system, hence they form a standard basis. the vectors of a standard basis are orthogonal to each other, i.e. normal
hence amy is normal and you can prove it mathematically
@wallhackio Just add another dimension, make the monorail system in 3D instead of 2D, then a vector basis can have 3 vectors