method to compute Integral(f(x), g(x))

[smichr]

Instantiation gets messy if we try to detect Integral(f(x), g(x)) in general. Perhaps a method like transform -- named weight? -- could be added so Integral(f(x), x).weight(g(x)) would give Integral(f(x)*g(x).diff(x), x).

[sylee957]

I think that this is called "Stieltjes Integral".
https://en.wikipedia.org/wiki/Riemann%E2%80%93Stieltjes_integral.