[169] in mathematical software users group
Re: grobner basis question
daemon@ATHENA.MIT.EDU (Reid M. Pinchback)
Wed May 31 16:46:10 1995
To: msug@MIT.EDU
Cc: sywong@MIT.EDU
Reply-To: msug@MIT.EDU
Date: Wed, 31 May 1995 16:44:40 EDT
From: "Reid M. Pinchback" <reidmp@MIT.EDU>
I just tried a stupid hack that seems to be doing something. The
computation is still in progress, but at least that error message
didn't come up.
Step 1: Define G1 as you indicated and "with(grobner)"
Step 2: H1 := subs(I=k,G1):
Step 3: H2 := diff(H1,t):
Step 4: gbasis( [ H1, H2, k^2+1 ], [t,x,a,b,k], plex );
In other words, I replaced "I" by the symbol "k". Since "I" is sqrt(-1),
so is k, and hence k^2+1=0. Although my ring theory is very rusty,
isn't it thus allowable to add k^2+1 to the set of generators for
the ideal? If anybody out there is more sure of this, please pipe up!
PS: In reading the ?gbasis help page, it says that you shouldn't add
parameters to the list of indeterminants. If any of [t,x,a,b] are
parameters, then perhaps you need to remove them from the list.
In other words, if they are a symbolic value belonging to the
coefficient ring, then they aren't one of the indeterminants.
===============================================================
= Reid M. Pinchback =
= Senior Faculty Liaison =
= Academic Computing Services, MIT =
= =
= Email: reidmp@mit.edu =
= URL: http://web.mit.edu/user/r/e/reidmp/www/home.html =
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