id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,work_issues,upstream,reviewer,author,merged,dependencies,stopgaps
12255,coeffs() fails on symbolic functions,mjo,burcin,"This was reported on sage-support:

  http://groups.google.com/group/sage-support/t/fa439b8dd28daaa8

As of 4.8.alpha6,

{{{
sage: g = function('g', var('t'))
sage: f = 3*g + g**2 + t
sage: f.coeffs(g)
...
ValueError: The name ""g(t)"" is not a valid Python identifier.
}}}

This didn't throw a ValueError in 4.7,

{{{
sage: f.coeffs(g)
[[g(t)^2 + t + 3*g(t), 0]]
}}}

but the result was still not the expected one. The correct answer would be,

{{{
sage: f.coeffs(g)
[[t, 0],[3, 1], [1, 2]]
}}}",defect,new,major,sage-5.10,symbolics,,,,,N/A,,,,,