#9880: Pynac comparison functions do not provide a SWO
-----------------------------+----------------------------------------------
Reporter: jpflori | Owner: burcin
Type: defect | Status: needs_work
Priority: major | Milestone: sage-5.10
Component: symbolics | Resolution:
Keywords: pynac | Work issues:
Report Upstream: N/A | Reviewers:
Authors: | Merged in:
Dependencies: | Stopgaps:
-----------------------------+----------------------------------------------
Old description:
> Here is a short example found by Burcin and reproducing the bug:
>
> {{{
> b = [var('b_%s'%i) for i in range(4)]
>
> precomp = (2^b_2 + 2)*(2^b_1 + 2^(-b_1) + 2^b_1*2^b_0 - 2^b_1*2^(-b_0)
> - 2^(-b_1)*2^b_0 - 2^(-b_1)*2^(-b_0) + 2^b_0 + 2^(-b_0) - 9) + (2^b_1 +
> 2^(-b_1) + 2^b_1*2^b_0 - 2^b_1*2^(-b_0) - 2^(-b_1)*2^b_0 -
> 2^(-b_1)*2^(-b_0) + 2^b_0 + 2^(-b_0) - 9)/2^b_2
>
> repl_dict = {b_0: b_0, b_3: b_1, b_2: b_3, b_1: b_2}
> P = precomp.substitute(repl_dict)
> P.expand()
> }}}
> This is already being discussed here: http://groups.google.com/group
> /sage-support/browse_thread/thread/7c85f02c76012722
>
> The following patches are for the Sage library to enable access to the
> PyNaC order and randomly test that it is a SWO:
>
> First build Pynac with patches from Burcin's pynac queue
> https://bitbucket.org/burcin/pynac-patches applied and install it.
>
> Then apply
> 1. [attachment:trac_9880_pynac_order.take2.rebased-5.5.rc0.patch]
> 1. [attachment:trac_9880_randomized_testing.patch]
> 1. [attachment:trac_9880-stable_operands.rebased-5.5.rc0.patch]
> 1. [attachment:trac_9880-fix_comparison-p1.rebased-5.5.rc0.patch]
> 1. [attachment:trac_9880-fix_variables_ordering.patch]
> 1. [attachment:trac_9880-doctest_for_9046.patch]
> 1.
> [attachment:trac_9880-fix_doctests_symbolic.take2.rebased-5.5.rc0.patch]
> 1. [attachment:trac_9880-fix_doctests-be.rebased-5.5.rc0.patch]
New description:
Here is a short example found by Burcin and reproducing the bug:
{{{
b = [var('b_%s'%i) for i in range(4)]
precomp = (2^b_2 + 2)*(2^b_1 + 2^(-b_1) + 2^b_1*2^b_0 - 2^b_1*2^(-b_0)
- 2^(-b_1)*2^b_0 - 2^(-b_1)*2^(-b_0) + 2^b_0 + 2^(-b_0) - 9) + (2^b_1 +
2^(-b_1) + 2^b_1*2^b_0 - 2^b_1*2^(-b_0) - 2^(-b_1)*2^b_0 -
2^(-b_1)*2^(-b_0) + 2^b_0 + 2^(-b_0) - 9)/2^b_2
repl_dict = {b_0: b_0, b_3: b_1, b_2: b_3, b_1: b_2}
P = precomp.substitute(repl_dict)
P.expand()
}}}
This is already being discussed here: http://groups.google.com/group/sage-
support/browse_thread/thread/7c85f02c76012722
The following patches are for the Sage library to enable access to the
PyNaC order and randomly test that it is a SWO:
First build Pynac with patches from Burcin's pynac queue
https://bitbucket.org/burcin/pynac-patches applied and install it.
Then apply
1. [attachment:trac_9880_pynac_order.take2.rebased-5.5.rc0.patch]
1. [attachment:trac_9880_randomized_testing.patch]
1. [attachment:trac_9880-stable_operands.rebased-5.5.rc0.patch]
1. [attachment:trac_9880-fix_comparison-p1.rebased-5.5.rc0.patch]
1. [attachment:trac_9880-fix_variables_ordering.patch]
1. [attachment:trac_9880-doctest_for_9046-rebased-5.9.patch]
1. [attachment:trac_9880-fix_doctests_symbolic.take2.rebased-5.9.patch]
1. [attachment:trac_9880-fix_doctests-be.rebased-5.9.patch]
--
Comment (by burcin):
I rebased the patches to 5.9.
Here is an example where `minpoly()` does not terminate:
{{{
sage: var('x')
x
sage: eqn = x^3 + sqrt(2)*x + 5 == 0
sage: a = solve(eqn, x)[0].rhs()
sage: a
-1/2*(1/18*sqrt(3)*sqrt(8*sqrt(2) + 675) - 5/2)^(1/3)*(I*sqrt(3) + 1) -
1/6*sqrt(2)*(I*sqrt(3) - 1)/(1/18*sqrt(3)*sqrt(8*sqrt(2) + 675) -
5/2)^(1/3)
sage: QQ[a]
}}}
or
{{{
sage: a.minpoly()
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/9880#comment:70>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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