Regular expression extraction from alphabet

Question

I have this Alphabet Σ = {k,l} so I do not understand how I can find the words equal bigger than 3
≤3 in L ((k|l)l*), should I use the words with 3 letters always starting with k or somthing else?

Answer 1

The regular expression for all words equal to or greater than $3$ in length using $\Sigma = \{ k , l \}$ in $ L =((k\mid l)l*)$ is : $$ (kll\mid lll)l* $$ Since it requires at least one instance of of $kll$ or $lll$ at the beginning