  Integer iteration rules such as n |-> {a n + b, c n +d} are studied as
minimal examples of the general process of multicomputation. Despite the
simplicity of such rules, their multiway graphs can be complex, exhibiting, for
example, emergent geometry and difficult questions of confluence.
Generalizations to rules involving non-integers and other functions are also
considered. Connections with physics and with various number-theoretic and
other questions are made.
