| junkrefs(str, r ' + refs0, st[r -- _type] .type, st) ⊦ sk = _type, junkref(str, r, st[r0 -- sk, val]), path∃+(str, r, r0, st) |
⊦ junkref(str, r, st) ↔ (∃ refs. refs ≠ [] ∧ refs .first = r ∧ junkrefs(str, refs, st[r -- _type] .type, st))
junkrefs(str, r ' + refs0, st[r -- _type] .type, st) ⊦ sk = _type, ∃ refs. refs ≠ [] ∧ refs .first = r ∧ junkrefs(str, refs, (st[r0 -- sk, val][r -- _type]) .type, st[r0 -- sk, val]), path∃+(str, r, r0, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st[r0 -- sk, val], r, str)]]