Question

Exercise 3.1.1: Write regular expressions for the following languages: * a) The set of strings over alphabet {a,b,c} containing at least one a and at least one b. b) The set of strings of O's and l’s whose tenth symbol from the right end is

Answer 1

solution oriven that ca2 set of storings Over alphabet {a,b,c} containing atleast one a and atleast one b + This symbol indicates that it will appears atleast one time * This appear symbol o times indicates that it may on many times atbt ci Example: ab, aabb, abbc , abc (6) set of strings of o's and is whase tenth symbol from right end is i

(100* here tenth symbol will always end with Example! 1010101010 ,1010, 10,- .. 1 Thank you