eliminated separate stamp -- NameSpace.define/merge etc. ensure uniqueness already;
fully authentic merge;
(benchmark Isabelle
:extrasorts ( T1)
:extrapreds (
(up_1)
)
:assumption (not (iff (iff (iff (iff (iff (iff (iff (iff (iff up_1 up_1) up_1) up_1) up_1) up_1) up_1) up_1) up_1) up_1))
:formula true
)