I'm having trouble negating a nested statement.
Let $\Sigma$ be an alphabet, $L\subseteq\Sigma^{*}$ a language and $n\in\mathbb{N}$ a natural number.
For all words $x\in{}L$ with $|x|\geq{}n$ there exists a partition $x=abc$ with $|ab|\leq{}n$ and $|b|\geq{}1$, so that for all $i\geq{}0$, $ab^{i}c$ is in $L$.
Suggested negation:
There exists a word $x\in{}L$ with $|x|\geq{}n$ for which all partitions are $x=abc$ with $|ab|\leq{}n$ and $|b|\geq{}1$, so that for all $i\geq{}0$, $ab^{i}c$ is not in $L$.
This doesn't sound quite right and I would appreciate suggestions for a correct negation.
The statement has the form :
Thus, its negation must be :
where $\lnot P$ is :