This question is meant to measure the gap between solving the main math-based benchmarks at the time of market creation, and contributing to real world mathematics.

The co first author requirement is loose: I will also accept an AI being credited with significant contributions to both deciding what to prove and the actual proof (merely contributing to the proof is not enough - I am trying to get at "the AI does the work of a mathematician" not "the AI does the work of a proof assistant"). I would also accept, for instance, the human author of the paper expressing that they would have named the AI as a coauthor if it was human, or saying that the result could not have been obtained without the assistance of the AI.