Vào lúc 12:33:10 UTC+7 ngày Thứ Sáu, 1 tháng 6, 2001, Qiong Cai đã viết:

Hi all,
Some codes from the book "First-Order logic
and Automated Theorem proving"(2nd) are as follows:
funcount(1).
newfuncount(N) :-
funcount(N),
retract(funcount(N)),
M is N + 1,
assert(funcount(M)).
reset :-
retract(funcount(_)),
assert(funcount(1)),
!.
But, when I actually call reset or newfuncount,
SWI-Prolog has a ERROR message:
ERROR: No permission to modify static procedure "funcount/1".
Could anyone tell me how to avoid this problem? Thanks

Yours
Qiong

I'm have to prove the equality of left and right neutral element of a semi group using PROLOG
here is my code:
m(m(x,y),z):- m(x,m(y,z)).
m(el,x)=x.
m(x,er)=x.
and the error is No permission to modify static procedure `(=)/2'
can some one please help me
Thanks so much

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On Thursday, 18 November 2021 at 09:21:26 UTC+1, Hoang Nguyen Duy wrote:

You should have opened a new thread, not reply to one that is from 2001:
next time, if you think the old discussion is relevant, please just put a link.

I'm have to prove the equality of left and right neutral element of a semi group using PROLOG
here is my code:
m(m(x,y),z):- m(x,m(y,z)).
m(el,x)=x.
m(x,er)=x.
and the error is No permission to modify static procedure `(=)/2'
can some one please help me
Thanks so much

That code makes no sense: looks like some kind of Python... Have you
gone through at least one tutorial before attempting to write any Prolog?

Julio

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