v.l0 = a.l0 + b.l0 v.l1 = a.l1 + b.l1 v.l2 = a.l2 + b.l2 v.l3 = a.l3 + b.l3 v.l4 = a.l4 + b.l4 return v.carryPropagate() } // Subtract sets v = a - b, and returns v. func (v *Element) Subtract(a, b *Element) *Element { // We first add 2 * p, to guarantee the subtraction won't underflow, and // then subtract b (which can be up to 2^255 + 2^13 * 19). v.l0 = (a.l0 + 0xFFFFFFFFFFFDA) - b.l0 v.l1 = (a.l1 + 0xFFFFFFFFFFFFE) - b.l1 v.l2 = (a.l2 + 0xFFFFFFFFFFFFE) - b.l2 v.l3 = (a.l3 + 0xFFFFFFFFFFFFE) -...