IssaiEdit

Could you clarify what you mean by "Issai"? The name could refer to different figures, and I want to write the article you want.

Possible interpretations: - Issai Schur (Иса́й Шур), the 20th‑century mathematician known for Schur’s lemma, Schur decomposition, and contributions to representation theory. - A biblical or historical figure named Issai (for example a transliteration variant of Yishai/Isaiah/Jesse), which would lead to a different article entirely. - another contemporary or historical person named Issai.

If you confirm which Issai you have in mind (and any preferred emphasis or length), I’ll draft the encyclopedia article in Markdown with the requested formatting and viewpoint.