Hydra: Difference between revisions

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simulator for Hydra/Antihydra's odd/even sequence
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Add Collatz rule plus references section
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{{TM|1RB3RB---3LA1RA_2LA3RA4LB0LB0LA}}
{{machine|1RB3RB---3LA1RA_2LA3RA4LB0LB0LA}}
Hydra is the 2-state 5-symbol machine {{TM|1RB3RB---3LA1RA_2LA3RA4LB0LB0LA}}.


https://www.sligocki.com/2024/05/10/bb-2-5-is-hard.html
It simulates the Collatz-like iteration
 
<math display="block">\begin{array}{l}
  C(2a+1, & b) & \to & A(3a+1, & b+2) \\
  C(2a,  & b) & \to & A(3a,  & b-1) & \text{if} & b>0 \\
  C(2a,  & 0) & \to          & \text{HALT}
\end{array}</math>
<br>
starting from <math>C(3,0)</math>.<ref>S. Ligocki, "[https://www.sligocki.com/2024/05/10/bb-2-5-is-hard.html BB(2, 5) is Hard (Hydra)] (2023). Accessed 22 July 2024.</ref>
 
It is closely related to the machine [[Antihydra]].<ref>S. Ligocki, "[https://www.sligocki.com/2024/07/06/bb-6-2-is-hard.html BB(6) is Hard (Antihydra)]". Accessed 22 July 2024.</ref>


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].
==Sources==
<references/>


[[Category:Stub]]
[[Category:Stub]]

Revision as of 16:40, 22 July 2024

Hydra is the 2-state 5-symbol machine 1RB3RB---3LA1RA_2LA3RA4LB0LB0LA (bbch).

It simulates the Collatz-like iteration

C(2a+1,b)→A(3a+1,b+2)C(2a,b)→A(3a,b−1)ifb>0C(2a,0)→HALT
starting from C(3,0).[1]

It is closely related to the machine Antihydra.[2]

A fast simulator for the odd/even sequence used by Hydra is available here.

Sources

  1. ↑ S. Ligocki, "BB(2, 5) is Hard (Hydra) (2023). Accessed 22 July 2024.
  2. ↑ S. Ligocki, "BB(6) is Hard (Antihydra)". Accessed 22 July 2024.