This is the subtraction function.
The result is A - B.
A and B can be floats, points, normals, vectors or colors.
The result will be a float if both A and B are floats.
The result will be a point if both A and B are points or B is a float.
The result will be a color if both A and B are colors or B is a float.
A type mis-match will result from the subtraction of points or colors
from floats or mixing colors and points.

The value to be decreased.
A can be a float, point, normal, vector or color.
Default is float.

The decrement must be either the same data type as A or a float.
Default is float.

This is the subtraction function.
The result is A - B.
A and B can be floats, points, normals, vectors or colors.
The result will be a float if both A and B are floats.
The result will be a point if both A and B are points or B is a float.
The result will be a color if both A and B are colors or B is a float.
A type mis-match will result from the subtraction of points or colors
from floats or of points from colors or vice versa.