When N(0) < 1 then l i m t → ∞ N ( t ) = 0 {\displaystyle lim_{t\to \infty }N(t)=0} , while when N(0) > 1 we have that l i m t → ∞ N ( t ) = 2 {\displaystyle lim_{t\to \infty }N(t)=2} .
