The floor of a real number \(x\) is the largest integer which is not larger than \(x\).
The notation \(\lfloor x \rfloor\) is used for this function. For example, \(\lfloor 2.1 \rfloor = 2\), \(\lfloor 3 \rfloor = 3\) and \(\lfloor -4.6 \rfloor = -5\).
