  In this work we extend and improve the results done in a previous work on
simulating Spiking Neural P systems (SNP systems in short) with delays using
SNP systems without delays. We simulate the former with the latter over
sequential, iteration, join, and split routing. Our results provide
constructions so that both systems halt at exactly the same time, start with
only one spike, and produce the same number of spikes to the environment after
halting.
