* Implement the improved division algorithm from https://dl.acm.org/doi/pdf/10.1145/800205.806321 (or something similar) * Optimize gcd_euclidean_improved up to 2 or more words * Optimize gcd_binary and extend the range * Lehmer GCD * Subquadratic GCD * Dan's GCD algorithm * XGCD * Handle pure real/imaginary input everywhere * Divisibility testing, valuation * Primality testing * Prime enumeration * Factoring (full and smooth) * Norm approximation / fast norm comparison
