Element.sqrtM1 constructor
Element.sqrtM1()
sqrtM1 is 2^((p-1)/4), which squared is equal to -1 by Euler's Criterion.
Implementation
factory Element.sqrtM1() => Element(
1718705420411056.toBigInt,
234908883556509.toBigInt,
2233514472574048.toBigInt,
2117202627021982.toBigInt,
765476049583133.toBigInt);