1RB1LC_1LC1RD_1LA0LB_0RB1RE_1RF0RA_---0RC
1RB1LC_1LC1RD_1LA0LB_0RB1RE_1RF0RA_---0RC (bbch) is a potentially probviously halting BB(6) TM with exponential runtime which was analysed by Racheline on Oct 25, 2025.[1]
Analysis by Racheline
https://discord.com/channels/960643023006490684/1239205785913790465/1431579799180148738
0^inf 1^(2n) C> 1^(2n+5) 0^inf halts for every n A(a,b) := 0^inf 1^a 0 C> 1^b 0^inf A(a,b) -> A(2a+4,b-a-1) if a is even and b>=a+3 A(a,b) -> A(2a+3,b-a) if a is odd and b>=a+4 A(a,a+3) -> A(2a+1,9) if a is odd A(a,a+2) -> A(1,2a+7) A(a,a+1) -> A(4,2a+4) A(a,b) -> A(a-b+1,2b+3) if a>=b>=4 A(a,3) -> halt if a>=2 A(a,2) -> A(a-3,7) if a>=4 start: A(2,9)
These rules have been simulated for 8e11 steps by Bricks.[2]