Existence of finitely presented nil but nonnilpotent algebras

Can an infinite-dimensional nil associative algebra be finitely presented? The specific target is a nonunital algebra over F₂ that is Jacobson radical but not nilpotent, whose unitization remains finitely presented, algebraic and infinite-dimensional.

Why it matters and what counts as progress

Why it matters: Finite presentation imposes a stronger algebraic finiteness condition than the known existence of infinite-dimensional nil algebras.

What counts as progress: Construct such an algebra with all stated properties or prove an obstruction for a restricted presentation class.

How the problem developed

  1. 19 Sept 2008 · Open question [1]

    Agata Smoktunowicz Recorded Ufnarovskij’s question whether every finitely presented nil algebra must be nilpotent, in a discussion of related nil-algebra problems.

  2. 23 Sept 2026 · Reported result [2]

    OpenAI Reported a finitely presented nonunital nil associative algebra over F₂ that is Jacobson radical but not nilpotent; its unitization is finitely presented and algebraic.

AI contribution

Sources

  1. Agata Smoktunowicz, The Jacobson radical of rings with nilpotent homogeneous elements
  2. OpenAI periodic-group and nil-algebra manuscript
  3. An infinite finitely presented periodic group
  4. Periodic-group formal target
  5. Ufnarovskij’s nil-algebra question
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Publication dates and editorial changes.