What are {} and [] functions?

Question

I see these functions in Bondy-Murty book about graph theory...

In book written: "The complete m-partite graph on n vertices in which each part has either [n/m] or {n/m} vertices is donated by T m,n. Show that..."

Can someone explain me what are these functions?

Answer 1

As a general rule, just look at the section on notation in your book:

Answer 2

$[n/m]$ means greatest integer function(or floor function), i.e. an integer $k$ s.t. $[n/m]-1<k\leq [n/m]$

and {n/m} means ceiling function i.e. an integer $k$ s.t. {n/m}$\leq k< ${n/m}+1.

For example, [$5/2=2.5]=2$ and {$5/2=2.5$}=$3$