For x exsits in real numbers, there is unique n exsists in integers s.t n<=x<n+1. denote this n as [x]. Thus, we obtain a function F: real numbers arrow real numbers, x arrow [x]. e.g. [-2.5]= -3.

Let a exsist in Integers show f is not continuous at a. ( use suitable sequences which converge to a )??????

Hope this makes sense thanks.