(t,i,j)-Cover

[math]\displaystyle{ (t,i,j) }[/math]-Cover --- [math]\displaystyle{ (t,i,j) }[/math]-покрытие.

Let [math]\displaystyle{ G = (V(G),E(G)) }[/math] be a graph. The set [math]\displaystyle{ S }[/math] of vertices is called a [math]\displaystyle{ (t,i,j) }[/math]-cover if every element of [math]\displaystyle{ S }[/math] belongs to exactly [math]\displaystyle{ i }[/math] balls of radius [math]\displaystyle{ t }[/math] centered at elements of [math]\displaystyle{ S }[/math] and every element of [math]\displaystyle{ V \setminus S }[/math] belongs to exactly [math]\displaystyle{ j }[/math] balls of radius [math]\displaystyle{ t }[/math] centered at elements of [math]\displaystyle{ S }[/math].