:= shiftRightBy51(r4) rr0 := r0.lo&maskLow51Bits + mul19(c4) rr1 := r1.lo&maskLow51Bits + c0 rr2 := r2.lo&maskLow51Bits + c1 rr3 := r3.lo&maskLow51Bits + c2 rr4 := r4.lo&maskLow51Bits + c3 v.l0 = rr0&maskLow51Bits + mul19(rr4>>51) v.l1 = rr1&maskLow51Bits + rr0>>51 v.l2 = rr2&maskLow51Bits + rr1>>51 v.l3 = rr3&maskLow51Bits + rr2>>51 v.l4 = rr4&maskLow51Bits + rr3>>51 } // carryPropagate brings the limbs below 52 bits by applying the reduction // identity (a * 2²⁵⁵ + b = a * 19 + b) to the l4 carry....