  A mechanism-free and symbol-agnostic conservation principle, the Conservation
of Hartley-Shannon Information (CoHSI) is predicted to constrain the structure
of discrete systems regardless of their origin or function. Despite their
distinct provenance, genomes and computer software share a simple structural
property; they are linear symbol-based discrete systems, and thus they present
an opportunity to test in a comparative context the predictions of CoHSI. Here,
without any consideration of, or relevance to, their role in specifying
function, we identify that 10 representative genomes (from microbes to human)
and a large collection of software contain identically structured nested
subsystems. In the case of base sequences in genomes, CoHSI predicts that if we
split the genome into n-tuples (a 2-tuple is a pair of consecutive bases; a
3-tuple is a trio and so on), without regard for whether or not a region is
coding, then each collection of n-tuples will constitute a homogeneous discrete
system and will obey a power-law in frequency of occurrence of the n-tuples. We
consider 1-, 2-, 3-, 4-, 5-, 6-, 7- and 8-tuples of ten species and demonstrate
that the predicted power-law behavior is emphatically present, and furthermore
as predicted, is insensitive to the start window for the tuple extraction i.e.
the reading frame is irrelevant.
  We go on to provide a proof of Chargaff's second parity rule and on the basis
of this proof, predict higher order tuple parity rules which we then identify
in the genome data.
  CoHSI predicts precisely the same behavior in computer software. This
prediction was tested and confirmed using 2-, 3- and 4-tuples of the
hexadecimal representation of machine code in multiple computer programs,
underlining the fundamental role played by CoHSI in defining the landscape in
which discrete symbol-based systems must operate.
