Functions
- From PSS paper, section 4.2.1, (https://link.springer.com/content/pdf/10.1007/3-540-44750-4_27.pdf)
- From the PSS paper, section 4.2.4, (https://link.springer.com/content/pdf/10.1007/3-540-44750-4_27.pdf)
- From PSS paper, section 4.2.3, (https://link.springer.com/content/pdf/10.1007/3-540-44750-4_27.pdf)