#6919: basic arithmetic using FLINT is broken (very serious!)
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Reporter: was | Owner: somebody
Type: defect | Status: new
Priority: blocker | Milestone: sage-4.1.2
Component: basic arithmetic | Keywords:
Reviewer: | Author:
Merged: |
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Mariah Lenox reported:
{{{
R.<x> = PolynomialRing(ZZ)
A = 2^(2^17+2^15) # note the 2 rather than the "s"
a = A * x^31
b = (A * x) * x^30
a == b # prints "False" ???
}}}
But
{{{
R.<x> = PolynomialRing(ZZ, implementation='NTL')
A = 2^(2^17+2^15) # note the 2 rather than the "s"
a = A * (x^31)
b = A * x * (x^30)
a == b
}}}
gives True. So this is definitely either a bug in FLINT (highly likely),
or a bug in our wrapper (much less likely, since our wrapper is so
generic:
{{{
cpdef RingElement _mul_(self, RingElement right):
r"""
Returns self multiplied by right.
EXAMPLES::
sage: R.<x> = PolynomialRing(ZZ)
sage: (x - 2)*(x^2 - 8*x + 16)
x^3 - 10*x^2 + 32*x - 32
"""
cdef Polynomial_integer_dense_flint x = self._new()
_sig_on
fmpz_poly_mul(x.__poly, self.__poly,
(<Polynomial_integer_dense_flint>right).__poly)
_sig_off
return x
}}}
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/6919>
Sage <http://sagemath.org/>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
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