Some Notes on Graph Automata, TilingSystems and Partition Logic

Introduce heuristically the newly definitioll (W. Thomas) for graph automata - using"tiles" to simulste the extension (over dag's) of the classical notions of transition moves; proposea sufficient condition for when graph automata can be reduced to (simpler) tiling systerms, whichis a generalisation of a Thomas' result; and finally study the logic sepcification of tiling systems(paticularly, over picture languages) by (existential) monadic partition logic, instead of theususal and stronger framework (E)MSQ.