Structure of Decidable Locally Finite Varieties

A mathematically precise definition of the intuitive notion of "algorithm" was implicit in Kurt Godel's [1931] paper on formally undecidable propo­ sitions of arithmetic. During the 1930s, in the work of such mathematicians as Alonzo Church, Stephen Kleene, Barkley Rosser and Alfred Tarski, Godel's idea evolved into the concept of a recursive function. Church pro­ posed the thesis, generally accepted today, that an effective algorithm is the same thing as a procedure whose output is a recur...