Bug report URL
Introducing mapFlipT2 and unwrapFlipT2 functions

mapFlipT2
    :: (f1 a1 b1 -> f2 a2 b2 -> f3 a3 b3)
    -> FlipT f1 b1 a1 -> FlipT f2 b2 a2 -> FlipT f3 b3 a3

unwrapFlipT2
    :: (FlipT f1 b1 a1 -> FlipT f2 b2 a2 -> FlipT f3 b3 a3)
    -> f1 a1 b1 -> f2 a2 b2 -> f3 a3 b3
Monad instance for FlipT Either a