In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

Example input: The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Example output: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.
Example explanation: The output sentence elaborates on the input sentence without changing its general meaning e.g. "tetralogy of young adult high fantasy novels".
Q: The diaphragm is a muscle that is at the bottom of the ribcage of mammals .
A:
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 .