Description issue.

arr2bin(1,2) == '11'
arr2bin(1,2,'a') == false

should be

arr2bin([1,2]) == '11'
arr2bin([1,2,'a']) == false

“In the tests, the point will never fall exactly on an edge of the polygon.”
Not true with tests.
And why is the 2nd test be inside while 4st be outside while they are all on the edge of its polygon?

another task:
with input "[ [ -1, -1 ], [ 9, -1 ], [ 4, 9 ] ], [ 1, -3 ]", The point is obvious outside the polygon, But it said it should be inside?

Interesting kata...
And as usual, some test examples really mad me... I promise I have never met so weird Molecule formulas...

Good job :)