14.13.6  Checking if points in space are collinear: is_collinear

See Section 13.16.2 for checking for collinearity in two-dimensional geometry.

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

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

Examples.

• Input:
  is_collinear([2,0,0],[0,2,0],[1,1,0])
  Output:

  1

• Input:
  is_collinear([2,0,0],[0,2,0],[0,1,1])
  Output:

  0