This Demonstration implements the mathematical model of HIV infection as described in . The notation used here, which differs from that of , is as follows:[more]
is the number of uninfected T cells.
is the number of infected T cells.
is the number of free virus particles.
Uninfected T cells are produced at a rate .
In the absence of a virus, uninfected T cells die at a rate .
Uninfected T cells turn into infected T cells at a rate .
Infected T cells die at a rate , releasing virus particles each time an infected T cell dies.
Finally, free virus particles are eliminated by the body at a rate .[less]
 M. A. Nowak and R. M. May, Virus Dynamics: Mathematical Principles of Immunology and Virology, New York: Oxford University Press, 2001.