<p><pre><code>    iterative loops are believed to be easier to reason about.
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This cannot be the case, because you can translate loops into recursion and vice versa, so every reasoning problem that one finds with loops is also a problem in reasoning about recursion and vice versa. If you look at the Hoare-logic rules this shows up clearly. In both case you need a suitably invariant, and you need a termination argument.