Can I enter rules into the data base?

[Sandeep]

Hi,
Is there a way I can enter rules in database? One way is to consult
the .pl file that has
rules in it. But I want to use assertz.
Like: call(assertz("less(X,Y) :- X < Y.")) and query q = Query('less
(1,2)') or something like that.
I tried a lot but could not get it with call. Any help is appreciated.

Cheers,
Sandeep

[yuce]

Hi Sandeep,

There is an example about that at the bottom of: http://code.google.com/p/pyswip/,
let me know if you have any problems with the code at Example (Using
Prolog) or Example (Pythonic Interface) sections of that page.

Best wishes,

Yuce

[dksr]

Hi yuce,

> There is an example about that at the bottom of:http://code.google.com/p/pyswip/,

The examples you have provided are for 'facts' not for 'rules'.
Actually, my problem is to use two prolog data bases seperately. If I
consult them, swi mixes both the files.
If I have to use the technique as suggested in
http://code.google.com/p/pyswip/wiki/HowToSimulateMultipleKnowledgebases,
it does not accept 'rules'.
In prolog consulting, I tried to kill the prolog session by issuing
the query 'halt'. But after that I could not start a new session using
Prolog().
For example:
----------------
prolog = Prolog()
rr = 'halt'
res = list(prolog.query(rr))

prolog2 = Prolog() # Now won't start a new session

Could you suggest any work around or trick to overcome these problems?

BTW, in the example at http://code.google.com/p/pyswip/wiki/HowToSimulateMultipleKnowledgebases
I get error when I execute it (in 64-bit linux)
To make it run, I have to change the following line (and other similar
lines)
call(assertz(parent("john", "bob")), test1)
to
call(assertz(parent("john", "bob")), module=test1)

Could you please check and correct the example?

Cheers,
Sandeep

[yuce]

You can enter rules using the "classic" interface to SWI-Prolog, you
can also use modules; the following example uses a module called
"test":

>>> from pyswip import Prolog
>>> p = Prolog()
>>> p.assertz('test:a(z)')
>>> p.assertz('test:b(z)')
>>> p.assertz('test:(c(X):-a(X),b(X))')
>>> list(p.query('test:c(X)'))
[{'X': 'z'}]

I hope that helps,

Best wishes,

Yuce

On Oct 5, 4:28 pm, dksr <dksre...@gmail.com> wrote:
> Hi yuce,
>
> > There is an example about that at the bottom of:http://code.google.com/p/pyswip/,
>
> The examples you have provided are for 'facts' not for 'rules'.
> Actually, my problem is to use two prolog data bases seperately. If I
> consult them, swi mixes both the files.

> If I have to use the technique as suggested inhttp://code.google.com/p/pyswip/wiki/HowToSimulateMultipleKnowledgebases,

> it does not accept 'rules'.
> In prolog consulting, I tried to kill the prolog session by issuing
> the query 'halt'. But after that I could not start a new session using
> Prolog().
> For example:
> ----------------
> prolog = Prolog()
> rr = 'halt'
> res = list(prolog.query(rr))
>
> prolog2 = Prolog()  # Now won't start a new session
>
> Could you suggest any work around or trick to overcome these problems?
>

> BTW, in the example athttp://code.google.com/p/pyswip/wiki/HowToSimulateMultipleKnowledgebases

[dksr]

Hi Yuce,
This is what I was looking for :-)
Thanks very much. Sorry for bothering as I did not find the above
example anywhere in the site.

Cheers,
Sandeep

[yuce]

I'm glad I could help. I will be adding the same example to the site.

Best wishes,

Yuce