+ c0 rr2 := r2.lo&maskLow51Bits + c1 rr3 := r3.lo&maskLow51Bits + c2 rr4 := r4.lo&maskLow51Bits + c3 *v = Element{rr0, rr1, rr2, rr3, rr4} v.carryPropagate() } // carryPropagateGeneri brings the limbs below 52 bits by applying the reduction // identity (a * 2²⁵⁵ + b = a * 19 + b) to the l4 carry. func (v *Element) carryPropagateGeneri() *Element { c0 := v.l0 >> 51 c1 := v.l1 >> 51 c2 := v.l2 >> 51 c3 := v.l3 >> 51 c4 := v.l4 >> 51 // c4 is at most 64 - 51 = 13 bits, so c4*19 is at most 18 bits, and...