Ciro Santilli @cirosantilli 37

 Incoming links: Antihydra

Antihydra  Updated 2025-05-26  +Created 2024-07-12

The Antihydra is the first hard-looking problem for BB(6), what some would classify as a Collatz-like problem.

It is documented on the Busy Beaver Challenge wiki at: wiki.bbchallenge.org/wiki/Antihydra

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Antihydra in Magic: The Gathering  Updated 2025-05-26  +Created 2025-05-21

Some dude recreated the antihydra on Magic: The Gathering at: aesort.com/antihydra, probably: x.com/IsaacKing314/status/1870637729375219740.

It is known that Magic: The Gathering is Turing complete, but it is cool to have a concrete specific example of an open problem in mathematics coded in it.

Figure 1.
Screenshot of the Antihydra in Magic: The Gathering construction
.

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BB(6) is hard  Updated 2025-05-26  +Created 2024-07-04

A hard problem ha been found for it, and it was called the "antihydra":

news.ycombinator.com/item?id=40864949 BB(6), The 6th Busy Beaver Number, is harder than a Collatz-like math problem
www.reddit.com/r/math/comments/1dubva0/finding_the_6th_busy_beaver_number_%CF%836_aka_bb6_is/ "Finding the 6th busy beaver number (Σ(6), AKA BB(6)) is at least as hard as a hard Collatz-like math problem called Antihydra":
www.reddit.com/r/compsci/comments/1duc62e/finding_the_6th_busy_beaver_number_%CF%836_aka_bb6_is/

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