(title) class FatRat
class FatRat is Cool does Rational[Int, Int]
A FatRat is a rational number stored with arbitrary size numerator and
denominator. Arithmetic operations involving a FatRat and optionally L<Int>
or L<Rat> objects return a FatRat , avoiding loss of precision.
Since, unlike L<Rat>, FatRat arithmetics do not fall back L<Num> at some
point, there is a risk that repeated arithmetic operations generate
pathologically large numerators and denominators.
There are two common ways to generate FatRat objects: through the
FatRat.new(Int, Int) constructor, which generates them from numerator and
denominator, or by calling the .FatRat method on an L<Int> or L<Rat>