Superposition of n i.i.d. one dimensional point processes according to :
On the Superposition of Renewal Processes
Author(s): D. R. Cox and Walter L. Smith
Source: Biometrika, Vol. 41, No. 1/2 (Jun., 1954), pp. 91-99
Published by: Oxford University Press on behalf of Biometrika Trust
Stable URL: http://www.jstor.org/stable/2333008 .
In test_superpositions.m usage is shown along with Montecarlo validation.
It needs the Matlab (R) Symbolic Toolbox. Tested on Matlab r2017b.