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.

The thoracic diaphragm , or simply the diaphragm , is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity .
The diaphragm is a muscle that is at the bottom of the ribcage of mammals .

In mathematical analysis , the maxima and minima ( the respective plurals of maximum and minimum ) of a function , known collectively as extrema ( the plural of extremum ) , are the largest and smallest value of the function , either within a given range ( the local or relative extrema ) or on the entire domain of a function ( the global or absolute extrema ) .
In mathematics , the maximum and minimum of a function are the largest and smallest value that the function takes at a given point .

Bolivia ( , -RSB- ; -RSB- ; -RSB- ; -RSB- ) , officially the Plurinational State of Bolivia ( -RSB- ) , is a landlocked country located in western-central South America .

Bolivia ( officially called Plurinational State of Bolivia ) is a country in South America .