Congruence based proofs of the recognizability theorems for free many-sorted algebras
arXiv:1808.08217 · doi:10.1093/logcom/exz032
Abstract
We generalize several recognizability theorems for free single-sorted algebras to the field of many-sorted algebras and provide, in a uniform way and without using neither regular tree grammars nor tree automata, purely algebraic proofs of them based on the concept of congruence.