Is it true that x* = {x*} for any string x ?
by ajiten from LinuxQuestions.org on (#6GES6)
In the end-of-chapter exercises in the book titled: Compiler Construction, by Anthony Reis; there is above problem.
As x is a string, and not a pattern given by a regex, so the statement must be true.
let x = abcd, then x^3 = abcdabcdabcd.
Say, on taking 0 iteration of the string x, have: e (empty string) both on the lhs, and the rhs.
Similarly for any number of positive power for * (i.e. >= 0), have postive number of concatenations of the string x.
As x is a string, and not a pattern given by a regex, so the statement must be true.
let x = abcd, then x^3 = abcdabcdabcd.
Say, on taking 0 iteration of the string x, have: e (empty string) both on the lhs, and the rhs.
Similarly for any number of positive power for * (i.e. >= 0), have postive number of concatenations of the string x.