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2 added 5 characters in body

Hi,

I need to prove the above claim. I can show that BB(2) >= 4 $BB(2)\ge 4$ by building a turing machine, but how can i show that BB(2) <= 4$BB(2) \le 4$?

Searched a lot over the web, and saw that Rado proved it in 1963.

Thanks.

1

# Busy Beaver - Proof for BB(2) = 4

Hi,

I need to prove the above claim. I can show that BB(2) >= 4 by building a turing machine, but how can i show that BB(2) <= 4?

Searched a lot over the web, and saw that Rado proved it in 1963.

Thanks.