Special square, pow u in final exponentiation

[emmansun]

for details, pls refer #35

[bwesterb]

Thanks for this. For ease of review, could you add more explicitly to each function what it does; what it assumes; and why it works.

[emmansun]

Thanks for this. For ease of review, could you add more explicitly to each function what it does; what it assumes; and why it works.

Hi @armfazh @bwesterb , i had tried my best to add more comments for all new added functions.