$X$ is a stochastic process and $T$ a stopping time of $\{F_t^X\}$. If $X_t(\omega) = X_t(\omega')$ for every $t\in[0,T(\omega)]\cap[0,\infty)$ and $\omega,\omega'\in \Omega$, then $T(\omega) = T(\omega')$.
Anyone could please give me a hint? Thank you very much.