reset(p0)
		return p0, blockChanged
	}

	// More than one predecessor

	if updating {
		// After the first approximation, i.e., when updating, results
		// can only get smaller, because initially backedge
		// predecessors do not participate in the intersection.  This
		// means that for the update, given the prior approximation of
		// startState, there is no need to re-intersect with unchanged