  We study transformations of 2-, 4- and 6-bit numbers in interactions between
traveling and stationary localizations in the Spiral Rule reaction-diffusion
cellular automaton. The Spiral Rule automaton is a hexagonal ternary-state
two-dimensional cellular automaton -- a finite-state machine imitation of an
activator-inhibitor reaction-diffusion system. The activator is self-inhibited
in certain concentrations. The inhibitor dissociates in the absence of the
activator. The Spiral Rule cellular automaton has rich spatio-temporal dynamics
of traveling (glider) and stationary (eater) patterns. When a glider brushes an
eater the eater may slightly change its configuration, which is updated once
more every next hit. We encode binary strings in the states of eaters and
sequences of gliders. We study what types of binary compositions of binary
strings are implementable by sequences of gliders brushing an eater. The models
developed will be used in future laboratory designs of reaction-diffusion
chemical computers.
