| refs2 .last = jvmref, r ∈ refs2, validrefs(str, r ' + refs2, ty, st), ∀ st, ty, str, refs0. # refs0 < # (r + refs2) → ( validrefs(str, refs0, ty, st) ∧ refs0 ≠ [] ∧ refs0 .last = jvmref → (∃ refs1. validrefs(str, refs1, ty, st) ∧ refs1 ≠ [] ∧ refs1 .last = jvmref ∧ refs0 .first = refs1 .first ∧ ¬ dups(refs1) ∧ refs1 ⊆ refs0)) ⊦ refs2 = [], ∃ refs. validrefs(str, refs, ty, st) ∧ refs ≠ [] ∧ refs .last = jvmref ∧ r = refs .first ∧ ¬ dups(refs) ∧ refs ⊆ refs .first ' + refs2 |
⊦ r ∈ refs ↔ (∃ refs0, refs1. refs = refs0 + (r + refs1))
refs2 .last = jvmref, ∃ refs0, refs1. refs2 = refs0 + (r + refs1), validrefs(str, r ' + refs2, ty, st), ∀ st, ty, str, refs0. # refs0 < # (r + refs2) → ( validrefs(str, refs0, ty, st) ∧ refs0 ≠ [] ∧ refs0 .last = jvmref → (∃ refs1. validrefs(str, refs1, ty, st) ∧ refs1 ≠ [] ∧ refs1 .last = jvmref ∧ refs0 .first = refs1 .first ∧ ¬ dups(refs1) ∧ refs1 ⊆ refs0)) ⊦ refs2 = [], ∃ refs. validrefs(str, refs, ty, st) ∧ refs ≠ [] ∧ refs .last = jvmref ∧ r = refs .first ∧ ¬ dups(refs) ∧ refs ⊆ refs .first ' + refs2
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (refs2, r)]]