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.
How about this?

```
<expr:or>
<l>
    <expr:and>
    <l>x</l><r>y</r>
    </expr>
</l>
<r>
    <expr:and>
    <l>p</l><r>q</r>
    </expr>
</r>
</expr>

```

Could also add `<expr:xor><l>x</l><r>y</r></expr>` and `<expr:not>x</expr>`.