This seems to be caused by having different ETuples. Contrast:
sage: explain_pickle(dumps(z))
...
pg_LaurentPolynomialRing_mpair(si2)(pg_unpickle_MPolynomial_libsingular(si2,
{pg_make_ETuple({0r:1r}, 2r):pg_make_rational('1')}), pg_make_ETuple({0r:-1r
}, 2r))
sage: explain_pickle(dumps(R.one()))
Indeed this is a bug, and the following version is even funnier
sage: z.is_one()
True
sage: z.is_constant()
False
Vincent
Le 16/01/2019 à 06:07, Henry Liu a écrit :
Hi all,
LaurentPolynomialRing does not handle constants correctly. Here is an
example:
sage: R. = LaurentPolynomialRing(
Hi all,
LaurentPolynomialRing does not handle constants correctly. Here is an
example:
sage: R. = LaurentPolynomialRing(QQ)
sage: z = x / x; z
1
sage: z.is_constant()
False
sage: z in ZZ
False
sage: z == R.one()
True
sage: z.parent()
Multivariate Laur
