Question

Find a regular expression for the set a^nb^m (n+m) is even

Answer 1

Answer:

L(r) = {w in {a,b}* : w contains at least 2 a's}

For that one I said {a^2n , b} because that guarantees a string like aab or aabaab etc. Not sure how to approach the one I posted about in the title. Possibly a solution might be a^2n, b^2m so its always even, but also 2 odd numbers like a^n b^3m is also always even. Am i allowed to set boundaries like n>=m?

Answer 2

Thank You mate for a lovely question