Possible Duplicate:
Pumping lemma for simple finite regular languages
The pumping lemma says that for any regular language $L$, there exists a constant $p$ such that any word $w$ in $L$ with length at least $p$ can be split into three substrings, $w = xyz$, where the middle portion $y$ must not be empty, such that the words $xz, xyz, xyyz, xyyyz, \ldots$ constructed by repeating $y$ an arbitrary number of times (including zero times) are still in $L$.
Consider a regular Language which contains only one string - the alphabet $a$. ie, $L = \{a\}$.
Now, in this $L$, what would be the value of $p$, and possible values of $x$, $y$ , $z$?
I am confused to the boundary cases of the pumping lemma.