v := &Int{false, nat{5, 2 + 1<<(_W-1), 1 << (_W - 1)}}

	r := new(Int)
	q, r := new(Int).QuoRem(u, v, r)
	const expectedQ64 = "18446744073709551613"
	const expectedR64 = "3138550867693340382088035895064302439801311770021610913807"
	const expectedQ32 = "4294967293"
	const expectedR32 = "39614081266355540837921718287"
	if q.String() != expectedQ64 && q.String() != expectedQ32 ||