dead integral code

Stream: maths

[Patrick Massot]

What's going on here? There is more than 100 lines of commented code. @Yury G. Kudryashov is this forgotten or you plan to uncomment it?

[Bryan Gin-ge Chen]

There's an explanation in a TODO in the module doc here.

[Yury G. Kudryashov]

Most of the code should be deleted now. I'll look into this tomorrow.

[Yury G. Kudryashov]

The exceptions are tendsto_integral_on_of_monotone, tendsto_integral_on_of_antimono, and integral_on_Union.