In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

In mathematics , and more specifically in graph theory , a graph is a structure amounting to a set of objects in which some pairs of the objects are in some sense " related " .
In mathematics , a graph is used to show how things are connected .

The lanthanide elements are the group of elements with atomic number increasing from 57 ( lanthanum ) to 71 ( lutetium ) .
From lanthanum ( 57 ) to lutetium ( 71 )

The Pakistan Citizenship Act of 1951 was enacted on 13 April 1951 ; stating the purpose of it is " to make provision for citizenship of Pakistan " .

The Pakistan Citizenship Act became law on 13 April 1951 .

