added proof reconstructon for Z3,
added certificates for simpler re-checking of proofs (no need to invoke external solvers),
added examples and certificates for all examples,
removed Unsynchronized.ref (in smt_normalize.ML)
(benchmark Isabelle
:extrafuns (
(uf_1 Int)
(uf_2 Int)
(uf_3 Int)
)
:assumption (not (= (* uf_1 (+ (+ uf_2 1) uf_3)) (+ (* uf_1 uf_2) (* uf_1 (+ uf_3 1)))))
:formula true
)