Carefull with the braces, and couldnt find the definite integration tool

I had a problem whith the braces, turns out some of them denote floor function , so i couldnt graph things well at first, and I still cant find where to calculate definite integrals, as it said somewhere in the introduction, but other than that, its really good.

Mmmm.... Mgf about Graphicus - Graphing Calculator