Well yeah, this one contains formats that make little sense (not seen anywhere else?). That's the only significant difference, and it's not a good one IMO.

I don't think so , especially because of the different ways to format the equation string

But, it's not easy to be sure and I will apologize if there is/are other katas with the same difficulty to properly analyse the equation string

There are similar ones but they're more strict in their formatting.

looks good

I add "- variables (a, x, x2, ...) begins with an alphabetic value and are composed with 1 to 5 alphanumeric values such as a21BC"

Surely this a duplicate... Have you checked how many such katas exist already?

You should also add something about what variables are allowed.

I had a round(...,5) and an explanation for the 5 digits precision

I add "spaces, power (^, **), operator * are allowed but not mandatory".
hoping it's sufficient

The examples in the description are not sufficient to explain the format of the provided string. You need to to actually specify what inputs are expected to be handled.

It would be good to do something about the rounding problem:
[-11.158063742718753, -1.1689346530760376] should equal [-11.158063742718754, -1.1689346530760376]

yes you're right ....

Could you please delete this tentative kata ?
I don't have the permission to do it by myself ...

Oups, I modified it

Duplicate: https://www.codewars.com/kata/58635f1b2489549be50003f1

Reference solution must be defined in test suite, not imported from user's code. I was able to pass with incorrect code, by providing reference solution.