J?rome Laurens <jerome.laurens <at> u-bourgogne.fr> writes:
> This is not really a problem of subst, in that case,
> integrate('diff(f(t)*diff(g(t),t),t),t,sqrt(beta),sqrt(alpha));
>
> just returns a formula that is not syntactically correct
> and prevent further calculations.
I see now that the problem is that integrate returns an expression
which contains something like 'diff(f(foo(x)), foo(x)) where that
should be 'at('diff(f(u), u), u = foo(x)) or something like that.
I suspect that's relatively easy to fix -- it is probably a minor
branch in integrate. I wouldn't be surprised to find subst in there ....
By the way, in the interest of getting bugs fixed, you might want
to explain what you expected to see and how it differs from the
actual output. Just saying "it's wrong" and waiting for others
to puzzle it out is probably less effective.
For what it's worth,
Robert Dodier