If the use of the absolute function |*x*| was allowed,
it is possible that we give a equation for *n*-gon by

where the is a periodic function in the period which
is defined in the domain
(Note thus .)
Though I hope to have simpler expression than this,
this is the simplest expression so far that I can give you.
This expression gives you a *n*-gon under the ideal precision
of calculation, since the infinite precision would be required
for the calculations at the vertexes.