I was reading Gavin Wood's polkadot paper and came across this:

"Tangle [17] is a novel approach to consensus systems.
Rather than arranging transactions into blocks and forming
consensus over a strictly linked list to give a globally
canonical ordering of state-changes, it largely abandons
the idea of a heavily structured ordering and instead
pushes for a directed acyclic graph of dependent transactions
with later items helping canonicalise earlier items
through explicit referencing. For arbitrary state-changes,
this dependency graph would quickly become intractable,
however for the much simpler UTXO model2
this becomes
quite reasonable. Because the system is only loosely coherent
and transactions are generally independent of each
other, a large amount of global parallelism becomes quite
natural. Using the UTXO model does have the effect
of limiting Tangle to a purely value-transfer “currency”
system rather than anything more general or extensible.
Furthermore without the hard global coherency, interaction
with other systems—which tend to need an absolute
degree knowledge over the system state—becomes impractical."

How does byteball deal with arbitrary state changes?