3 Nov 04:16 2004

### Question:TimeStamp

```hi,

Is there a system clock in powerloom. Are there any
commands that use time like before, after where i can
compare two time stamps. Please let me know this.

Thanks.

kolli

__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
```
3 Nov 04:16 2004

### Question:TimeStamp

```hi,

Is there a system clock in powerloom. Are there any
commands that use time like before, after where i can
compare two time stamps. Please let me know this.

Thanks.

kolli

__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
```
4 Nov 00:28 2004

### Basic Question: Comparision and Arithmetic operators

```hi,

could someone help me solving this. Are there any
comparison operators like <,>,=.....(like 30<45) and
so on. I need to use the difference of two numbers in
the command. Does powerloom support such arithmetic
know and please provide me with an example too if its
not too much.

Thanks.

Kolli

__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
```
4 Nov 01:23 2004

### Re: Basic Question: Comparision and Arithmetic operators

```Take a look at pl-kernel-kb.ste. Search for "Arithmetic Relations and
Functions". There's also an '=' and a 'DIFFERENT' relation, which work for
more than just numbers.

Octav

--On Wednesday, November 03, 2004 15:28 -0800 kolli kavita
<lovelykavitha <at> yahoo.com> wrote:

> hi,
>
> could someone help me solving this. Are there any
> comparison operators like <,>,=.....(like 30<45) and
> so on. I need to use the difference of two numbers in
> the command. Does powerloom support such arithmetic
> know and please provide me with an example too if its
> not too much.
>
> Thanks.
>
> Kolli
>
>
>
> __________________________________
> Do you Yahoo!?
> Check out the new Yahoo! Front Page.
> www.yahoo.com
>
```

4 Nov 01:38 2004

### Re: Basic Question: Comparision and Arithmetic operators

```
On Nov 3, 2004, at 3:28 PM, kolli kavita wrote:

> hi,
>
> could someone help me solving this. Are there any
> comparison operators like <,>,=.....(like 30<45) and
> so on. I need to use the difference of two numbers in
> the command. Does powerloom support such arithmetic
> know and please provide me with an example too if its
> not too much.

Yes, these operations are built in.  Like the rest of
PowerLoom, prefix notation is used.  Arithmetic operations
are actually implemented as constraints, so a single
unbound variable in any position is supported.

If you look at the number of employees section of the
tutorial in the PowerLoom manual, you will also see some
sections on the arithmetic comparisons.

Examples follow:

Processing check-types agenda...
TRUE

```

4 Nov 03:22 2004

### Re: Question:TimeStamp

```
On Nov 2, 2004, at 7:16 PM, kolli kavita wrote:

> hi,
>
> Is there a system clock in powerloom. Are there any
> commands that use time like before, after where i can
> compare two time stamps. Please let me know this.

There are the basic functions in the underlying Stella system that
would allow for this type of reasoning.  In our internal research
version we also have developed PowerLoom level access for specific
timepoint reasoning that will do this as well -- but that will need to
await the next release of PowerLoom.  We hope to have that out around
the end of this year, but are a bit short of time to go through the
release, documentation and testing process.

Unfortunately, the timepoint reasoning code does rely on some updates
to both PowerLoom and Stella, so it can't be easily added to the 3.0.2
version.

As a preview of what would be supported in the next version of
PowerLoom, I offer the following trace:

? (deffunction timestamp-of (?x ?y))
|f|TIMESTAMP-OF

? (assert (timestamp-of this (timepoint-kb/timepoint-of "now")))
|P|(= (TIMESTAMP-OF THIS) (/TIMEPOINT-KB/TIMEPOINT-OF now))

```