Question: I have a published application for ipad which is a newstand app.

Ever since the 5.1 iOs update when I try to download any issues using 
NKAssetDownload I get a very long delay until the update starts.

I get no error message or anything it just takes a really long time(5-10mins)
for the download to start.

After the download starts it proceeds normally and finishes without any further 
delay or errors.

If I could have any suggestions on what the problem might be or how I could 
possibly debug it I would really appreciate it as this is a live app and 
customers are starting to go crazy.

Thank you in advance.

Answer: 
Armatus answer looks good to me. I consider the left and right element as redundant. Having a logical expression it doesn't matter if i evaluate them left right or right left. 

```
 <expr type="or">
    <expr type="and">
        <sig>x</sig>
        <sig>y</sig>
    </expr>
    <expr type="and">
        <sig>p</sig>
        <sig>q</sig>
    </expr>
</expr>

```

for example:
 `(x & y) | (p & q)` is the same as `(q & p) | (y & x)`

furthermore its possible to add more than just two signals.
Your first "quick stab" looks perfectly reasonable to me, except perhaps for the outer 'expr' element, which doesn't add much value.