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What is an existential type?
... one type and one value. The universal proof is an entire family of values indexed by type (or a mapping from types to values).
So the difference between the two types you specified is as follows:
T = ∃X { X a; int f(X); }
This means: A value of type T contains a type called X, a value a:X, an...
MongoDB: Find a document by non-existence of a field?
...
+1. However, keep in mind that such queries can't use indexing and might be very slow on large collections.
– mnemosyn
Dec 19 '11 at 21:12
10
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.append(), prepend(), .after() and .before()
...
See:
.append() puts data inside an element at last index and
.prepend() puts the prepending elem at first index
suppose:
<div class='a'> //<---you want div c to append in this
<div class='b'>b</div>
</div>
when .append() executes it will look li...
Maximum Year in Expiry Date of Credit Card
...
<?php
$y = gmdate("Y");
$x = 20;
$max = ($y + $x);
while ($y <= $max) {
echo "<option value='$y'>$y</option>";
$y = $y + 1;
}
?>
sh...
IE10 renders in IE7 mode. How to force Standards mode?
...imple doctype declaration is enough. But even a document as short as this falls back to IE7 mode:
5 Answers
...
Notepad++ add to every line
...ck Ctrl+ F.
Choose Regular Expression
*Find What: "^" (which represents index of the each line - "PREFIX").
Replace with : "anyText"*
For Suffix on each line: Follow the same steps as above "Replace ^ with $" . That's it.
...
Is there any way to put malicious code into a regular expression?
...o solve. These may only show up on particular input data, but one can generally create one wherein this doesn’t matter.
Which ones these are will depend somewhat on how smart the regex compiler you’re using happens to be, because some of these can be detected during compilation time. Regex com...
embedding image in html email
...ere for simple example: oracle-base.com/articles/misc/EmailFromOraclePLSQL.php Note that this link does not show embedded images approach, but has detail to get you going.
– tbone
Mar 9 '12 at 15:19
...
Cannot delete directory with Directory.Delete(path, true)
...s why someone may be enumerating the folder or reading its files:
search indexers
anti-viruses
backup software
The general approach to deal with spurious failures is to try multiple times, pausing between the attempts. You obviously don't want to keep trying forever, so you should give up after ...
Using getopts to process long and short command line options
...or using the bash builtin getopts to mimic long options. That solution actually makes a short option whose character is "-". So you get "--" as the flag. Then anything following that becomes OPTARG, and you test the OPTARG with a nested case.
This is clever, but it comes with caveats:
getopts ca...