Infinitesimal Fourier Transformation for The Space of Functionals
  The purpose is to formulate a Fourier transformation for the space of functionals, as an infinitesimal meaning. We extend ${\bf R}$ to $ ^{\star}(^{\ast}{\bf R})$ under the base of nonstandard methods for the construction. The domain of a functional is the set of all internal functions from a $ ^{\ast}$-finite lattice to a $ ^{\ast}$-finite lattice with a double meaning. Considering a $ ^{\ast}$-finite lattice with a double meaning, we find how to treat the domain for a functional in our theory of Fourier transformation, and calculate two typical examples. 
Takashi Nitta and Tomoko Okada