src/FOLP/ROOT.ML

only replace unknowns of type nat with known integer numbers, don't alias unknown values in Z3's counterexamples with known integers

(*  Title:      FOLP/ROOT.ML
    Author:     Martin Coen, Cambridge University Computer Laboratory
    Copyright   1993  University of Cambridge

Modifed version of Lawrence Paulson's FOL that contains proof terms.

Presence of unknown proof term means that matching does not behave as expected.
*)

use_thys ["FOLP"];