# On Plus of empty string

We know $L^+=L^\star\backslash\{\epsilon\}$. How do we interpret that $\{\epsilon\}^+=\{\epsilon\}$?

• "We know that $L^+ = L^*\setminus\{\varepsilon\}$." No we don't. – David Richerby Apr 8 '17 at 23:14
• @DavidRicherby I meant when $\epsilon\notin L$ and $L$ is an alphabet set – T.... Apr 9 '17 at 20:28