  Causal Graph Dynamics extend Cellular Automata to arbitrary, bounded-degree,
time-varying graphs. The whole graph evolves in discrete time steps, and this
global evolution is required to have a number of physics-like symmetries:
shift-invariance (it acts everywhere the same) and causality (information has a
bounded speed of propagation). We add a further physics-like symmetry, namely
reversibility. KEYWORDS: Bijective, invertible, injective, surjective,
one-to-one, onto, Cayley graphs, Hedlund, Block representation, Lattice-gas
automaton, Reversible Cellular Automata.
