Green's machines: Difference between revisions

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(List of Milton Green's Machines)
Β 
(they are not champions πŸ₯€)
Β 
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In 1964, Milton W. Green hand-crafted a family of fast-growing Turing Machines with n-states, 2-symbols for all <math>n \ge 4</math>.<ref>Milton W. Green. β€œA Lower Bound on Rado’s Sigma Function for Binary Turing Machines”, ''Proceedings of the IEEE Fifth Annual Symposium on Switching Circuits Theory and Logical Design'', 1964, pages 91–94, [https://doi.org/10.1109%2FSWCT.1964.3 https://doi.org/10.1109/SWCT.1964.3]</ref> This family grows roughly as fast as the Ackermann function<math display="block">BB_{2n} \approx 3 \uparrow^{n-2} 3</math> Β 
In 1964, Milton W. Green hand-crafted a family of fast-growing Turing Machines with n-states, 2-symbols for all <math>n \ge 4</math>.<ref>Milton W. Green. β€œA Lower Bound on Rado’s Sigma Function for Binary Turing Machines”, ''Proceedings of the IEEE Fifth Annual Symposium on Switching Circuits Theory and Logical Design'', 1964, pages 91–94, [https://doi.org/10.1109%2FSWCT.1964.3 https://doi.org/10.1109/SWCT.1964.3]</ref> This family grows roughly as fast as the Ackermann function:<math display="block">BB_{2n} \approx 3 \uparrow^{n-2} 3</math>
Β 
Over the years, these Turing Machines lost champion status. The last machines to lose champion status were BB(9), BB(10), and BB(11). In August 2024, Racheline discovered the better bounds <math>BB(9) > 10 \uparrow\uparrow 1820</math> and <math>BB(10) > 10 \uparrow\uparrow\uparrow\uparrow\uparrow 4 </math>.


== Machines ==
== Machines ==
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|-
|-
|4
|4
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1RD1RA}}
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1RD1RA|halt}}
|7
|7
|-
|-
|5
|5
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1RE1RC}}
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1RE1RC|halt}}
|13
|13
|-
|-
|6
|6
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1RF1RD}}
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1RF1RD|halt}}
|35
|35
|-
|-
|7
|7
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1RG1RE}}
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1RG1RE|halt}}
|22,961
|22,961
|-
|-
|8
|8
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1RH1RF}}
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1RH1RF|halt}}
|<math> \frac{7 \cdot 3^{93} - 3}{2} </math>
|<math> \frac{7 \cdot 3^{93} - 3}{2} </math>
|-
|-
|9
|9
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1RI1RG}}
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1RI1RG|halt}}
|<math> > 3 \uparrow\uparrow 31 </math>
|<math> > 3 \uparrow\uparrow 31 </math>
|-
|-
|10
|10
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1RJ1RH}}
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1RJ1RH|halt}}
|<math> > 3 \uparrow\uparrow 3 \uparrow\uparrow 4 </math>
|<math> > 3 \uparrow\uparrow 3 \uparrow\uparrow 4 </math>
|-
|-
|11
|11
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1RK1RI}}
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1RK1RI|halt}}
|<math> > 3 \uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow 2 </math>
|<math> > 3 \uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow 2 </math>
|-
|-
|12
|12
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1LK1RH_0LL0LK_1RL1RJ}}
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1LK1RH_0LL0LK_1RL1RJ|halt}}
|<math> > 3 \uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow 4 </math>
|<math> > 3 \uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow 4 </math>
|-
|-
|13
|13
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1LL1RI_0LM0LL_1RM1RK}}
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1LL1RI_0LM0LL_1RM1RK|halt}}
|<math> > 3 \uparrow\uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow\uparrow 2 </math>
|<math> > 3 \uparrow\uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow\uparrow 2 </math>
|-
|-
|14
|14
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1LK1RH_0LL0LK_1LM1RJ_0LN0LM_1RN1RL}}
|{{TM|1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1LK1RH_0LL0LK_1LM1RJ_0LN0LM_1RN1RL|halt}}
|<math> > 3 \uparrow\uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow\uparrow 4 </math>
|<math> > 3 \uparrow\uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow\uparrow 4 </math>
|-
|-
|15
|15
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1LL1RI_0LM0LL_1LN1RK_0LO0LN_1RO1RM}}
|{{TM|1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1LL1RI_0LM0LL_1LN1RK_0LO0LN_1RO1RM|halt}}
|<math> > 3 \uparrow\uparrow\uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow\uparrow\uparrow 2 </math>
|<math> > 3 \uparrow\uparrow\uparrow\uparrow\uparrow 3 \uparrow\uparrow\uparrow\uparrow\uparrow 2 </math>
|
|}
|}



Latest revision as of 08:51, 28 August 2025

In 1964, Milton W. Green hand-crafted a family of fast-growing Turing Machines with n-states, 2-symbols for all .[1] This family grows roughly as fast as the Ackermann function:

Over the years, these Turing Machines lost champion status. The last machines to lose champion status were BB(9), BB(10), and BB(11). In August 2024, Racheline discovered the better bounds and .

Machines

# States TM Sigma Score
4 1LB1RZ_0LC1LC_0LD0LC_1RD1RA (bbch) 7
5 1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1RE1RC (bbch) 13
6 1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1RF1RD (bbch) 35
7 1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1RG1RE (bbch) 22,961
8 1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1RH1RF (bbch)
9 1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1RI1RG (bbch)
10 1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1RJ1RH (bbch)
11 1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1RK1RI (bbch)
12 1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1LK1RH_0LL0LK_1RL1RJ (bbch)
13 1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1LL1RI_0LM0LL_1RM1RK (bbch)
14 1LB1RZ_0LC1LC_0LD0LC_1LE1RA_0LF0LE_1LG1RD_0LH0LG_1LI1RF_0LJ0LI_1LK1RH_0LL0LK_1LM1RJ_0LN0LM_1RN1RL (bbch)
15 1LD1LB_1LZ1LA_0LB1LD_0LE0LD_1LF1RC_0LG0LF_1LH1RE_0LI0LH_1LJ1RG_0LK0LJ_1LL1RI_0LM0LL_1LN1RK_0LO0LN_1RO1RM (bbch)

External Links

References

  1. ↑ Milton W. Green. β€œA Lower Bound on Rado’s Sigma Function for Binary Turing Machines”, Proceedings of the IEEE Fifth Annual Symposium on Switching Circuits Theory and Logical Design, 1964, pages 91–94, https://doi.org/10.1109/SWCT.1964.3