Has anybody wondered if you could have an infinit'simal calculus based on the limit of PRODUCTS rather than series?
I've been playing with such for the last 2 or so years and want others to look at and/or comment on. I call any such calculus (actually there are several) MULTIGRAL CALCULUS. I've knocked up a website (www.geocities.com/multigrals2000) where I outline some multigrals. Please visit, download some articles, sign the guestbook - okay?

The "simplest" multigral is the 'limit of the product of f(x) to the POWER of delta x as delta x tends to zero'. For suitable f(x) it equals e^(the integral of ln(f(x))dx). Such have a interesting role in estimating long-term modes of stochastic recursive equations like P --> (1+b-d)*P where b and d are the stochastic birth and death rate respectively. Please see the above website and tell me what you think. Also see https://math2.org/math/paper/sect1-2.htm for similar.