### 11.16.2 Check if three points are collinear in the plane: is_collinear

See section 12.13.6 for checking for collinearity in three-dimensional geometry.

The is_collinear command is a Boolean function which takes as argument a list or sequence of points.

is_collinear returns 1 if the points are collinear and returns 0 otherwise.
Input:

is_collinear(0,1+i,-1-i)

Output:

1

Input:

is_collinear(i/100, 1+i, -1-i)

Output:

0