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check if INT is good primt for IDEAL
IsSigmaGoodPrime(p: INT, I: IDEAL): BOOL |
This function checks if
p
is a sigma-good prime for
I
,
that is if it is good for modular reduction of the sigma-reduced
GBasis of
I
.
See article Abbott, Bigatti, Robbiano
"Ideals modulo p"
(
https://arxiv.org/abs/1801.06112
)
/**/ use QQ[x,y,z];
/**/ I := ideal(2*x*y^2 -1, 3*x^3*y -1);
/**/ ReducedGBasis(I);
[x*y^2 -1/2, x^2 +(-2/3)*y, y^3 +(-3/4)*x]
/**/ DenSigma(I);
12
/**/ IsSigmaGoodPrime(2,I);
false
/**/ IsSigmaGoodPrime(32003,I);
true
|