⊦ newref(r, st) ↔ r ≠ jvmref ∧ (∀ rk. rk ∈ st → rk .ref ≠ r)
⊦ r ≠ jvmref ∧ (∀ rk. rk ∈ st → rk .ref ≠ r) ↔ r ≠ jvmref ∧ ¬ r ∈ st
[[CONCRETESIMPRULES : ()]]