Hydra: Difference between revisions
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A fast simulator for the odd/even sequence used by Hydra is available [http://nethack4.org/esolangs/fasthydra.zip here]. | A fast simulator for the odd/even sequence used by Hydra is available [http://nethack4.org/esolangs/fasthydra.zip here]. | ||
== Name == | |||
The name ''Hydra'' references the Ancient Greek legend: just as the legendary creature was growing 2 heads after losing 1 head, the $b$ counter that is kept on the right side of the tape is either decremented by or 1 incremented by 2 (approximately with equal frequency if modelled as a random process; in reality it depends on the parity of $a$). The Hydra dies (halts) when the last head is cut. | |||
==Sources== | ==Sources== | ||
Revision as of 07:49, 23 July 2024
Hydra is the 2-state 5-symbol machine 1RB3RB---3LA1RA_2LA3RA4LB0LB0LA (bbch).
It simulates the Collatz-like iteration
starting from .[1]
It is closely related to the machine Antihydra.[2]
A fast simulator for the odd/even sequence used by Hydra is available here.
Name
The name Hydra references the Ancient Greek legend: just as the legendary creature was growing 2 heads after losing 1 head, the $b$ counter that is kept on the right side of the tape is either decremented by or 1 incremented by 2 (approximately with equal frequency if modelled as a random process; in reality it depends on the parity of $a$). The Hydra dies (halts) when the last head is cut.
Sources
- ↑ S. Ligocki, "BB(2, 5) is Hard (Hydra) (2023). Accessed 22 July 2024.
- ↑ S. Ligocki, "BB(6) is Hard (Antihydra)". Accessed 22 July 2024.