id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,merged,author,reviewer,upstream,work_issues,branch,commit,dependencies,stopgaps
14229,Remove vacuous solutions from solve,ppurka,burcin,"Sometimes solve and its variants tend to report vacuous solutions. A recent one from [http://ask.sagemath.org/question/2324/how-to-print-out-maxima-commands-being-used-by ask.sagemath] is the following:
{{{
sage: x,y = var('x,y')
sage: solve([x^2*y^2 <= x^2*y, x^2*y^2 > x^2*y],[x,y])
[[x == 0, 1 < y, 0 != 0], [x == 0, y < 0, 0 != 0]]
}}}
Shouldn't we remove these meaningless solutions? The attached patch contains a potential solution. If it seems reasonable, then similar changes could be introduced in `solve_ineq`.
The output of the above command after this patch is as expected:
{{{
sage: x,y = var('x,y')
sage: solve([x^2*y^2 <= x^2*y, x^2*y^2 > x^2*y],[x,y])
[]
}}}
----
If you can translate this to maxima proper, please feel free to do so and submit a patch upstream.
----
'''Workaround''': call `maxima_calculus(""domain: real"")` before `solve` (see comment 12).",enhancement,needs_work,major,sage-6.4,symbolics,,,kcrisman jondo,,,,N/A,,,,,