Fm

For each m >= 2, Fm is a computational model based on editing a finite unbounded string on an alphabet of m letters. It is derived from Brainfuck in the spirit of the Wang program formulation of Turing machines, by using only the five instructions '+' '<' '>' '[' ']' and by applying a cyclic ordering to the alphabet, with '+' changing a letter to the next letter in cyclic order.

Computational class
F2 has been proved Turing-complete without reference to the Turing completeness of other Brainfuck languages, by directly simulating a universal tag system in F2. All Fm languages are therefore Turing-complete, because they can easily simulate F2.