We prove that for a given deterministic top-down transducer with look-ahead it is decidable whether or not its translation definable (1) by linear tree (2) homomorphism. present algorithms construct equivalent such transducers if they exist.

Schaefer introduced a framework for generalized satisfiability problems on the Boolean domain and characterized the computational complexity of such problems. We investigate an algebraization of Schaefer’s framework in which the Fourier transform is used to represent constraints by multilinear polynomials in a unique way. The polynomial representation of constraints gives rise to a relaxation o...

Abstract Given a Henselian valuation, we study its definability (with and without parameters) by examining conditions on the value group. We show that any valuation whose group is not closed in divisible hull definable language of rings, using one parameter. Thereby strengthen known results. Moreover, this case, parameter optimal sense cannot obtain parameters. To end, present construction meth...