Machines and Languages Here are some informal descriptions of languages. Write down a regular expression to define each language formally. Make a note of any ambiguity in the informal descriptions....

Machines and Languages

Here are some informal descriptions of languages. Write down a regular expression to define each language formally. Make a note of any ambiguity in the informal descriptions. The alphabet for all the languages below is {0,1}.

1. Any non-empty string that ends with a 1.
2. Any non-empty string that starts and ends with two 1’s (tricky!).

3. Any string that starts with either 010 or 101, followed by zero or more 0’s and 1’s in any order.