Numbers with errors (uncertainties)

Dear ROOTers,

In my work I often integrate spectra and then normalize them, all of the time keeping track of the statistical error. TH1::IntegralAndError() is fine, however, if I want to divide then two integrals with their associated errors, I have to hard-code the error propagation formula (messy and error-prone).
For this purposes I already made a calculator (software) which handles error propagation. You can check it out on sourceforge:

I like it a lot so I was wondering if it would be useful to implement it in ROOT. Not the whole calculator, but the base class (let’s call it TErrNum) and overloading all the operators +,-,*,/ etc to properly propagate the errors.
I can also imagine that e.g. TErrorGraphs can be constructed by providing two arrays of TErrNum.

best regards,