In the ODE where $y'=f(y(t))$ and $y(0)=yo$.
The omega limit set $w(yo)$ is positively invariant and also negatively invariant.
I want to prove first that its positively invariant and then prove its negatively invariant.
But how do I show that using a flow function ($phi(y,t)$) given that I know only the definition and the identity of flow function and very little understanding of the concept of flow function.
Thankyou for the help!