Longest increasing subsequence

Naumberg

Problem:

"Let [itex]x_1, ..., x_n[/itex] be i.i.d random variables uniformly on [0,1]. Let [itex]X[/itex] be the length of the longest increasing subsequence of [itex]x_1, ..., x_n[/itex]. Show that [itex]E[X] \ge (1-o(1))(1-e^{-1}) \sqrt{n}[/itex]."

Hi forum!

Using the Erdos' lemma I can only deduce that [itex]E[X] \ge \frac{1}{2} \sqrt{n}[/itex], which is a weaker bound unfortunately.

I would appreciate any further ideas!

Thanks for your help,
Michael

Stephen Tashi

What does the notation "[itex] o(1) [/itex]" mean in this context?