5 problems

Coexistence conjecture. Introducing different $?$ symbols for rules a)--d) and adopting the exact symmetric rules for the backward transitions should allow the four rules to coexis…

A one-dimensional reversible Turing machine is a reversible Turing machine whose tape is one-dimensional. Reversible physical universality means physical universality in the specif…

Let $A$ be a finite alphabet of even order, let $n\geq3$, let $S_A$ be the symmetric group on $A$, and let $TG(i,\alpha,o)$ denote the $i$-ary Toffoli gate with permutation…

Let $A=\\{1,\dots,k\\}$ be a finite alphabet of even cardinality, and let $n\geq 2$. Write $B_n(A)$ for the group of invertible maps on $A^n$, let $(1,\dots,k)$ denote the correspo…

Coherence-preservation conjecture. Instantiating a coherent-memory context with an incoherent process should produce an incoherent term.