<p><pre><code>    compare computations in brainfuck to computations in C. 
</code></pre>
I&#x27;d suggest that this is an orthogonal issue. It&#x27;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 <i>formal</i> reasoning is of the same complexity.