Louck has developed a relation between surreal numbers up to the first
transfinite ordinal omega and aspects of iterated trapezoid maps. In
this paper, we present a simple connection between transfinite iterate
s of the inverse of the tent map and the class of all the surreal numb
ers. This connection extends Louck's work to all surreal numbers. In p
articular, one can define the arithmetic operations of addition, multi
plication, division, square roots, etc., of transfinite iterates by co
nversion of them to surreal numbers. The extension is done by transfin
ite induction. Inverses of other unimodal onto maps of a real interval
could be considered and then the possibility exists of obtaining diff
erent structures for surreal numbers. (C) 1997 Academic Press.