In this parametrizisation fusion (pointwise product of densities) is trivial: The new set of parameters `(c, F, H)` for fusing k densities of this form is <img width="129" alt="Screen Shot 2022-08-22 at 18 05 01" src="https://user-images.githubusercontent.com/1923437/185967023-234fbb91-fd36-4ec0-a881-1d98b99b31b4.png">