Congruence based proofs of the recognizability theorems for free many-sorted algebras
Juan Climent Vidal, Enric Cosme Llópez
TL;DR
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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.
