Nov 20:
define circular arcs, prove that the intersection of two circular arcs
is a circle point, derive equations for circle points, discuss implementation
of some primitives. Show how to do the comparison of x-coordinates by
repeated squaring. Then show that the repeated squaring strategy works for
every expression with integer operands and operators +, -, 
,
and
.
State the basic separation bound theorem and show how it can be
used in a numerical sign test
Handout: Circle Points and Predicates on Circle Points