preprint available (Kock and Reyes)

The following preprint A. Kock and G.E. Reyes: Fractional Exponent Functors and Categories of Differential Equations is available via the Home Page http://www.mi.aau.dk/~kock/ or directly by ftp (200 KB) ftp://ftp.imf.au.dk/pub/kock/ODE5.ps (also available in .dvi format, 100 KB). Abstract: This paper grew out of a question/suggestion of Lawvere: to use the "amazing right adjoints" (= fractional exponents) of Synthetic Differential Geometry, to get information on the category of second order differential equations. As a byproduct of our investigations, we derive some information about the strength (enrichment) of fractional exponent functors in general.