Preservation Theorems in Finite Model Theory ? Eric Rosen ? ?
نویسندگان
چکیده
We develop various aspects of the nite model theory of L k (9) and L k 1! (9). We establish the optimality of normal forms for L k 1! (9) over the class of nite structures and demonstrate separations among descriptive complexity classes within L k 1! (9). We establish negative results concerning preservation theorems for L k (9) and L k 1! (9). We introduce a generalized notion of preservation theorem and establish some positive results concerning \generalized preservation theorems" for rst-order deenable classes of nite structures which are closed under extensions.
منابع مشابه
Preservation Theorems in Finite Model Theory
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