⊦ newref(r, st) ↔ r ≠ jvmref ∧ ¬ r ∈ st
⊦ r ∈ st ∧ ¬ r ∈ st0 → ¬ st ⊆ st0
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, r)]]