Checking whether points in space are collinear

See Section 26.15.2 for checking for collinearity in 2D geometry.

The is_collinear command determines whether or not points in space are collinear.

is_collinear takes L, a list or sequence of points.
is_collinear(L) returns 1 if the points in L are collinear, it returns 0 otherwise.

is_collinear([2,0,0],[0,2,0],[1,1,0])

is_collinear([2,0,0],[0,2,0],[0,1,1])