This makes a good benchmark LLMs:

``` look at this paper: https://arxiv.org/pdf/2603.21852

now please produce 2x+y as a composition on EMLs ```

Opus(paid) - claimed that "2" is circular. Once I told it that ChatGPT have already done this, finished successfully.

ChatGPT(free) - did it from the first try.

Grok - produced estimation of the depth of the formula.

Gemini - success

Deepseek - Assumed some pre-existing knowledge on what EML is. Unable to fetch the pdf from the link, unable to consume pdf from "Attach file"

Kimi - produced long output, stopped and asked to upgrade

GLM - looks ok