Check if lines are in a bundle: is_harmonic_line_bundle

### 12.16.16 Check if lines are in a bundle: is_harmonic_line_bundle

The is_harmonic_line_bundle command takes as argument a list or sequence of lines.

is_harmonic_line_bundle returns

1. 1 if the lines pass through a common point
2. 2 if the lines are parallel
3. 3 if the lines are the same
4. 0 otherwise

Input:

is_harmonic_line_bundle([line(0,1+i),line(0,2+i),line(0,3+i),line(0,1)])

Output:

1