Non-halting Turing machine: Difference between revisions

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== Classification ==
== Classification ==
* Cyclers
* Cyclers
* Translated cyclers
* Translated cyclers
* Bouncers
* Bouncers (first seen in 2x2)
* Bells
* Bells
** Exponential bells (first seen<ref>By "first seen" I mean either minimal in number of states '''or''' minimal in number of symbols</ref> in 3x2)
** Exponential bells (first seen<ref>By "first seen" I mean either minimal in number of states '''or''' minimal in number of symbols</ref> in 3x2)
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** Quartic bells (first seen in 5x2)
** Quartic bells (first seen in 5x2)
** etc...
** etc...
* Counters
** Irregular bells
* Counters (first seen in 2x2)
** Regular
** Regular
** Irregular
** Irregular
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* Spaghetti
* Spaghetti
* Cellular automata (first seen in 5x2 and 3x3)
* Cellular automata (first seen in 5x2 and 3x3)
Sometimes phase transitions can occur. For example, {{TM|1RB1RC_1LC0RA_0LB0LD_1LA1LD}} starts out as an irregular bell but phase transitions into a translated cycler with period 4222 at step 29754825.
== Records ==
=== Translated cycler preperiod ===
* 3x2: 101 (proven): {{TM|1RB1LB_0RC0LA_1LC0LA}} (period = 24)
* 4x2: 119,120,230,102 (current champion): {{TM|1RB1LC_0LA1RD_0RB0LC_1LA0RD}} (period = 966,716)
* 2x4: 293,225,660,896 (current champion): {{TM|1RB2LA0RA3LA_1LA1LB3RB1RA}} (period = 483,328)
=== Translated cycler period ===
* 3x2: 92 (proven): {{TM|1RB0LA_0RC1LA_1LC0RB}} (preperiod = 0)
* 4x2: 212,081,736 (current champion): {{TM|1RB0LA_0RC1RD_1LD0RB_1LA1RB}} (preperiod = 5,248,647,886)
* 2x4: 33,209,131 (current champion): {{TM|1RB0RA3LB1RB_2LA0LB1RA2RB}} (preperiod = 63,141,841)


By the uncomputability of the Busy Beaver function, it is reasonable to believe that there can never be a complete classification of behaviors of Turing machines for arbitrarily high numbers of states.
By the uncomputability of the Busy Beaver function, it is reasonable to believe that there can never be a complete classification of behaviors of Turing machines for arbitrarily high numbers of states.

Revision as of 23:05, 3 November 2024

(Very rough sketches and outlines)

Classification

  • Cyclers
  • Translated cyclers
  • Bouncers (first seen in 2x2)
  • Bells
    • Exponential bells (first seen[1] in 3x2)
    • Cubic bells (first seen in 3x2)
    • Quartic bells (first seen in 5x2)
    • etc...
    • Irregular bells
  • Counters (first seen in 2x2)
    • Regular
    • Irregular
    • Exponential/tetration...
  • Hybrid (counter-counter, bouncer-counter)
  • Fractals
    • Cube-like fractals (first seen in 4x2)
    • Christmas tree fractals (first seen in 2x4)
  • Spaghetti
  • Cellular automata (first seen in 5x2 and 3x3)

Sometimes phase transitions can occur. For example, 1RB1RC_1LC0RA_0LB0LD_1LA1LD (bbch) starts out as an irregular bell but phase transitions into a translated cycler with period 4222 at step 29754825.

Records

Translated cycler preperiod

  • 3x2: 101 (proven): 1RB1LB_0RC0LA_1LC0LA (bbch) (period = 24)
  • 4x2: 119,120,230,102 (current champion): 1RB1LC_0LA1RD_0RB0LC_1LA0RD (bbch) (period = 966,716)
  • 2x4: 293,225,660,896 (current champion): 1RB2LA0RA3LA_1LA1LB3RB1RA (bbch) (period = 483,328)

Translated cycler period

  • 3x2: 92 (proven): 1RB0LA_0RC1LA_1LC0RB (bbch) (preperiod = 0)
  • 4x2: 212,081,736 (current champion): 1RB0LA_0RC1RD_1LD0RB_1LA1RB (bbch) (preperiod = 5,248,647,886)
  • 2x4: 33,209,131 (current champion): 1RB0RA3LB1RB_2LA0LB1RA2RB (bbch) (preperiod = 63,141,841)

By the uncomputability of the Busy Beaver function, it is reasonable to believe that there can never be a complete classification of behaviors of Turing machines for arbitrarily high numbers of states.

  1. By "first seen" I mean either minimal in number of states or minimal in number of symbols