| maxpath(str, r0, st) = # refs, maxpath(str, r, st) = 1 + # refs0, st[r -- i '] = refval(r0), refs ∈ validrefset(str, r0, st), maxpath(str, r, st) ≤ maxpath(str, r0, st), 0 < st[r -- _length] .intval, validrefs(str, r ' + refs0, st[r -- _type] .type, st), # refs0 < maxpath(str, r0, st), is_array(str, r, st), i < st[r -- _length] .intval, 0 ≤ i ⊦ validrefset(str, r, st) = ∅, # validrefset(str, r, st) = 0, validrefset(str, r0, st) = ∅, # validrefset(str, r0, st) = 0, has_reffield((r ' + refs0) .last, st), r ∈ refs0, dups(refs0), cyclic(str, r, st), junkref(str, r, st) |
⊦ is_valid_ref(str, r, st) → ( refs ∈ validrefset(str, r, st) ↔ refs ≠ [] ∧ refs .first = r ∧ ¬ has_reffield(refs .last, st) ∧ ¬ dups(refs) ∧ validrefs(str, refs, st[r -- _type] .type, st))
¬ is_valid_ref(str, r0, st), maxpath(str, r0, st) = # refs, maxpath(str, r, st) = 1 + # refs0, st[r -- i '] = refval(r0), refs ∈ validrefset(str, r0, st), maxpath(str, r, st) ≤ maxpath(str, r0, st), 0 < st[r -- _length] .intval, validrefs(str, r ' + refs0, st[r -- _type] .type, st), # refs0 < maxpath(str, r0, st), is_array(str, r, st), i < st[r -- _length] .intval, 0 ≤ i ⊦ validrefset(str, r, st) = ∅, # validrefset(str, r, st) = 0, validrefset(str, r0, st) = ∅, # validrefset(str, r0, st) = 0, has_reffield((r ' + refs0) .last, st), r ∈ refs0, dups(refs0), cyclic(str, r, st), junkref(str, r, st)
is_valid_ref(str, r0, st), maxpath(str, r0, st) = # refs, maxpath(str, r, st) = 1 + # refs0, st[r -- i '] = refval(r0), refs ≠ [] ∧ refs .first = r0 ∧ ¬ has_reffield(refs .last, st) ∧ ¬ dups(refs) ∧ validrefs(str, refs, st[r0 -- _type] .type, st), maxpath(str, r, st) ≤ maxpath(str, r0, st), 0 < st[r -- _length] .intval, validrefs(str, r ' + refs0, st[r -- _type] .type, st), # refs0 < maxpath(str, r0, st), is_array(str, r, st), i < st[r -- _length] .intval, 0 ≤ i ⊦ validrefset(str, r, st) = ∅, # validrefset(str, r, st) = 0, validrefset(str, r0, st) = ∅, # validrefset(str, r0, st) = 0, has_reffield((r ' + refs0) .last, st), r ∈ refs0, dups(refs0), cyclic(str, r, st), junkref(str, r, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (st, r0, str, refs)]]