Multitape automata and finite state transducers with lexicographic weights

Finite state transducers, multitape automata and weighted automata have a lot in common. By studying their universal foundations, one can discover some new insights into all of them. The main result presented here is the introduction of lexicographic finite state transducers, that could be seen as intermediate model between multitape automata and weighted transducers. Their most significant advantage is being equivalent, but often exponentially smaller than even smallest nondeterministic automata without weights. Lexicographic transducers were discovered by taking inspiration from Eilenberg’s algebraic approach to automata and Solomonoff’s treatment of a priori probability. Therefore, a quick and concise survey of those topics is presented, prior to introducing lexicographic transducers.