I first solved this kata very straightforwarly without numpy and no special trick, your original code was probably quite inefficient, I advocate for no reduction too.

no reduction, this is 4 kyu

It's not really the number of test, but rather their size, the last five tests are very big.

I originally intended for people to use external libraries such as numpy to do the math part and didn't think people would bother to write the code themselves.

The final tests ended up, accidentally, being an extra challenge for those who wanted to give a go at making a more efficient algorithm.

If you just want to get it over with, use imports. Now, if you want a challenge, try to write it yourself.

see description

<b not <=b