-- The basic functionality allows one to express difference/update
-- equations in state space form.  This should be general enough to
-- allow for further symbolic manipulation.

-- z x = a * x

ffloor = fromIntegral . floor
frac x = x - ffloor x


-- eqs = \((x),(p)) ->       ((frac x + p), ())  ...


f1 x y = x * y

f x y = a * b where
    a = x - y
    b = x + y