Else-Branch of tail recursion requires negation of the input condition

[Feliix42]

Currently, writing a recursion algorithm like this:

fn transact(...) {
    // ...
    if (is_empty(remap_paths)) {
        new_maze
    } else {
        transact(new_maze, remap_paths)
    }
}

produces an semantically incorrect algorithm as the result of is_empty is used directly for determining, whether another recursion step is necessary, although is ought to be the other way around. For this case, negating the output is required.