Program correctness on finite fields Program correctness on finite fields

L. Csirmaz:

Program correctness on finite fields

An asserted program is presented whose correctness is provable by the Floyd-Hoare-Naur method in each finite field separately, which, however, admits no universal derivation, i.e. one which would work on all but finitely many finite fields of a given characteristic. Also, it is proved in general that if "executing a program twice with the same input, the outputs agree" is a provable property, then the output of the program is first order definable from the input.

Key words: Finite fields, pseudofinite fields, program correctness, Floyd-Hoare derivation.