id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
12438 Definite integral should not depend on the dummy variable Andrey Novoseltsev Burcin Erocal "Consider the following:
{{{
sage: f(x) = x; f
x |--> x
sage: integral(f, x)
x |--> 1/2*x^2
sage: integral(f, x, 0, 1)
x |--> 1/2
}}}
The last integral has not ""happened"" to be constant - it does not depend on x mathematically, so it should not depend on x in Sage.
Multivariate case:
{{{
sage: f(x, y) = x + y
sage: f
(x, y) |--> x + y
sage: integral(f, x, 0, 1)
(x, y) |--> y + 1/2
sage: _(3)
y + 1/2
}}}
`integral(...)` here should return a symbolic function that depends on y only, so that the last evaluation gives `7/2` (and there are no warning about unnamed evaluation - the order of variables is the same as for the original function with one variable dropped).
See discussion here: http://groups.google.com/group/sage-devel/browse_thread/thread/1309eeae0714be79" defect closed major sage-5.1 symbolics fixed sd40.5 Karl-Dieter Crisman Jason Grout sage-5.1.beta3 Andrey Novoseltsev Karl-Dieter Crisman, Benjamin Jones, Douglas McNeil N/A