I vaguely feel like `if ( ! $a || ! $b )` can be simplified. Any time I have multiple negations, I find it really hard to think about the logic of the statement, so I break it down into a logic grid:

`0, 0 = 1
0, 1 = 1
1, 0 = 1
1, 1 = 0`

Oh, indeed. That's just `if ( ! ( $a && $b ) )` which I suspect is easier to reason about.