src/HOL/SMT/Examples/cert/z3_arith_quant_17

merged with converted/relocated copy of http://isabelle.in.tum.de/repos/isabelle-jedit/rev/93d884afa74b

(benchmark Isabelle
:assumption (not (exists (?x1 Int) (implies (forall (?x2 Int) (implies (<= ?x1 ?x2) (< 0 ?x2))) (< 0 ?x1))))
:formula true
)