I have a question about the regular operation 'star' in computational theory.
IF $A$ is $\{ good , bad \}$ then
$A^* = \{ \varepsilon , good, bad , goodgood, goodbad, badgood , \dots \}$
What is the exact "regular operation" mean then ?
Can we use $^*$ operation only for regular language ? I don't think so.
$L = \{0^n1^n \mid n \ge 0 \}$ is a famous example of a non-regular language, but it seems we can create $L^*$?