Neither "is X" nor "is not X" correct.
The answer to the question "Is Y X?" is that if X is a blurred circle, then neither "is X" nor "is not X" is correct. https://gyazo.com/12b5f8efd78dc73aaa69f16141d272a0
---
This page is auto-translated from /nishio/「Xである」も「Xでない」も正しくない using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.