compare computations in brainfuck to computations in C. I'd suggest that this is an orthogonal issue. It's better to compare two otherwise identical languages

compare computations in brainfuck to computations in C. I'd suggest that this is an orthogonal issue. It's better to compare two otherwise identical languages, one where Turing-completeness is achieved by loops, another where the same is done by recursion. (Or a language that offers both). Then formal reasoning is of the same complexity.