y*(1.0 + (u - v)*(x - t*u) - u*v)/((1.0 - u*v)*(-t + u*x))
y*(1 + (u - v)*(x - t*u) - u*v) ------------------------------- (1 - u*v)*(-t + u*x)
y*(1 + (u - v)*(x - t*u) - u*v) ------------------------------- (1 - u*v)*(-t + u*x)
y*(1 + (u - v)*(x - t*u) - u*v) ------------------------------- (-1 + u*v)*(t - u*x)
y*(1 + (u - v)*(x - u*t) - v*u) ------------------------------- (1 - v*u)*(-t + u*x)
/ 2 \ -\y + u*x*y - t*y*u - u*v*y - v*x*y + t*u*v*y/ ------------------------------------------------ 2 t - u*x + v*x*u - t*u*v
/ 2 \ -y*\1 + u*x - t*u - u*v - v*x + t*u*v/ ---------------------------------------- (-1 + u*v)*(-t + u*x)