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,b1)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.