// 2^250 - 2^50 t1.Square(&t1) } t0.Multiply(&t1, &t0) // 2^250 - 1 t0.Square(&t0) // 2^251 - 2 t0.Square(&t0) // 2^252 - 4 return v.Multiply(&t0, x) // 2^252 - 3 -> x^(2^252-3) } // sqrtM1 is 2^((p-1)/4), which squared is equal to -1 by Euler's Criterion. var sqrtM1 = &Element{1718705420411056, 234908883556509, 2233514472574048, 2117202627021982, 765476049583133} // SqrtRatio sets r to the non-negative square root of the ratio of u and v. // // If u/v is square, SqrtRatio returns r and 1. If u/v...