No Victor, you got it backwards, you should evaluate these integrals non-rigorously if you can, and rigorously if you must.
Doron ZeilbergerConventional wisdom, fooled by our misleading "physical intuition", is that the real world is "continuous", and that discrete models are necessary evils for approximating the "real" world, due to the innate discreteness of the digital computer.
Doron ZeilbergerLet me also remind you that zero, like all of mathematics, is fictional and an idealization. It is impossible to reach absolute zero temperature or to get perfect vacuum. Luckily, mathematics is a fairyland where ideal and fictional objects are possible.
Doron Zeilberger