# Does '!=' equivelent to 'is not'

Lie Lie.1296 at gmail.com
Wed Jun 18 21:14:02 CEST 2008

```On Jun 18, 7:26 am, "Gabriel Genellina" <gagsl-... at yahoo.com.ar>
wrote:
> En Tue, 17 Jun 2008 09:09:41 -0300, Derek Martin <c... at pizzashack.org>
> escribió:
>
> > On Tue, Jun 17, 2008 at 04:33:03AM -0300, Gabriel Genellina wrote:
> >> > Basically 'a is b' and 'not(a is b)' is similar to 'id(a) == id(b)'
> >> > and 'not(id(a) == id(b))'
>
> >> No.
>
> > Sure it is... he said "similar"... not identical.  They are not the
> > same, but they are similar.
>
> 'equality' and 'identity' are similar too, so the whole answer would make
> no sense in that case. You can't explain identity based on things that
> aren't identical. A fine grained question for a fine grained difference
> requires a fine grained answer.

In my defense, I admit I have the tendency to forget (purposefully)
fine-grained differences if I thought that the difference was not
significant enough in the context of speaking. The OP asked about !=
and 'is not', so I explained in terms of those being equality and
identity testing respectively. To give a more concise and easy to
understand example, I said that 'is not' is like using testing the
'id()' of the objects. Since (I think) the difference between != and
'is not' is much larger compared to the difference between 'is not'
and 'id() test', I thought I could consider 'is not' and 'id() test'
as "equivalent" in the context of this thread: 'Does != is equivalent
to "is not"'.

Either way, I'm sorry that I failed to put explicit notice that 'is
not' and 'id() testing' isn't exactly the same either.

> > Saying a flat "no" alone, without qualifying your statement is
> > generally interpreted as rude in English...  It's kind of like how you
> > talk to children when they're too young to understand the explanation.
> > Yucky.
>
> I didn't meant to be rude at all - and I apologize to Mr. Lie.

I don't deserve the apology because the mistake is on me and I didn't
feel offended, in fact I'm delighted someone could point out my
mistake.

> The
> explanation for such strong "No" was in the paragraph below it (the idea
> was to say: "No to this, yes to that")

```