Thanks again for fixing the log.
I SOLVED this kata and it was immensely satisfying.
Definitely was harder than I initially envisioned.
You are right, I now respect elevators :)

Yes, thank you. It seems correct now.
Thanks!

I guess I am confused. Not sure if you are saying I am printing the wrong input to the expected output.
I was saying that something changed as The tests were generating seeming correct expected output.
Now you can see in the above example that the expected output shows that the elevator stops at floor 6.
there are no passengers there.

Here is a copy and paste:
Up and down
[0, 1, 2, 3, 2, 0] should equal [0, 1, 2, 3, 6, 5, 3, 2, 0]
Log
((), (), (4, 4, 4, 4), (), (2, 2, 2, 2), (), ()) , 2

Did something just change?
It appears something is broken in the tests.
For example, for queue: ((3, 3, 3, 3, 3, 3), (), (), (), (), (4, 4, 4, 4, 4, 4), ()) , 5
It says, should equal [0, 1, 2, 3, 6, 5, 3, 2, 0]

Another example: ((3, 3, 3, 3, 3, 3), (), (), (), (), (4, 4, 4, 4, 4, 4), ()) , 5
Says, should equal [0, 3, 5, 4, 0, 3, 5, 4, 0]

I am using Python 3.6

It seems I saw that reported correctly 1 day ago.

It turned out that I had a bug in the parsing code and my algorithm correctly detected the rank of the matrix.

I appreciate the non-insulting parts of the explanation and thank you for taking the time to answer.
Evidently the gauss-jordan algorithm I used did not detect a problem as it returned a properly row reduced matrix.
1 0 | 1
0 1 | 0

I wiil check that.
Thanks.

You lost the bet!
Next time don't bet. I cannot imagine anyone who appreciates such comment.

If the kata said that no varaible can be zero, then it would be clear.

I don't understad since I have found a solution where y=0.
You can clearly see this.
It is also unique.

So the test:
@Test.it('No solution')
def b():
tester(solve("x+2y=1", "2x=2-4y"), None)

expects none, yet this is not true as the solution:
{'x': 1.0, 'y': 0.0} <- is valid not None

Are you suggesting that y cannot be ZERO?