# How to express the set of all ternary strings of odd length as regular expression?

I know that the lanuguage of all strings of odd length {a,b} can be expressed as: (a+b)((a+b)(a+b))^*.

But what about an odd length over (a,b,c}?

• I edited the question to make sense; please note the differences in phrasing and why they are relevant! – Raphael Mar 24 '17 at 18:47
• Welcome to Computer Science! What have you tried? Where did you get stuck? We do not want to just hand you the solution; we want you to gain understanding. However, as it is we do not know what your underlying problem is, so we can not begin to help. See here for tips on asking questions about exercise problems. If you are uncertain how to improve your question, why not ask around in Computer Science Chat? – Raphael Mar 24 '17 at 18:47
• In particular, why do you think you have to do something very different from the binary case? – Raphael Mar 24 '17 at 18:48

(a+b+c)((a+b+c)(a+b+c))^*.
It is trivial since when you can do odd length over a language with 2 symbols, then why can't it be extended??