1RB1LD_1RC0LE_1LA1RE_0LF1LA_1RB0RB_---0LB

Unsolved problem:

Does this TM halt? If so, how many steps does it take to halt?

1RB1LD_1RC0LE_1LA1RE_0LF1LA_1RB0RB_---0LB (bbch) is a probviously halting BB(6) Cryptid analyzed by Racheline on 9 February 2025.

Analysis by Racheline

https://discord.com/channels/960643023006490684/1239205785913790465/1337994337790853181

if it halts, it seems to do so after at least around 1.24^1.24^530 steps (around 10^(3*10^48)). it's a shift-overflow counter but the counting is chaotic, like in the two chaotic counter 3x3 holdouts. here's my python code for figuring out the sequence of states hitting a given bit, in case anyone wants to see if they can do something with it (0 is E, 1 is A and 2 is D):

a = [0]
ats = [1]
atlen = 1
for _ in range(77):
    b = []
    bts = []
    btlen = 0
    t = 0
    bit = 0
    starting = 1
    while starting or bit:
        starting = 0
        for i in range(len(a)):
            s = a[i]
            t += ats[i]
            btlen += ats[i]
            if s == 0:
                bit = 1 - bit
                b.append(bit)
                bts.append(t)
                t = 0
            elif s == 1 and bit:
                b.append(2)
                bts.append(t)
                t = 0
            elif s == 2:
                b.append(bit)
                bts.append(t)
                t = 0
        t += atlen - ats[-1]
    a = b
    ats = bts