User blog comment:Bubby3/Notation provably equivalent to BMS pair sequences/@comment-35470197-20190530005229

> However, people seriously doubt the termination of pair sequences of BM4, which act very similarily to them.

Who doubts? BM4 is completely equivalent to BM2.3 by definition. More precisely, the original description of BM4 is not formalised, and BM2.3 is defined in terms of mathematics. Therefore in order to talk about the comparison, we need to formalise BM4. Then Bashicu, the creator of BM4, aggreed that BM2.3 is formalises BM4. Therefore the formalisation of BM4 is just BM2.3.