| junkref(str, r, st), validFields(r0, fis, st), is_valid_ref(str, r0, st) ⊦ junkref(str, r, update(r0, fis, st)), path∃(str, r, r0, st), _type ∈ fis |
⊦ junkref(str, r, st) ↔ (∃ refs. refs ≠ [] ∧ refs .first = r ∧ junkrefs(str, refs, st[r -- _type] .type, st))
∃ refs. refs ≠ [] ∧ refs .first = r ∧ junkrefs(str, refs, st[r -- _type] .type, st), validFields(r0, fis, st), is_valid_ref(str, r0, st) ⊦ junkref(str, r, update(r0, fis, st)), path∃(str, r, r0, st), _type ∈ fis
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, r, str)]]